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Masaomi Tanaka

Section

Graduate School of Science

Job title

Professor

Degree

博士（理学）（東京大学）
修士（理学）（東京大学）

researchmap

https://researchmap.jp/masaomi.tanaka

J-GLOBAL ID

201801017271880314

e-Rad No.

70586429

Research History 5

2024/04 - Present

Tohoku University　Graduate School of Science Department of Astronomy
2018/04 - 2024/03

Tohoku University　Graduate School of Science, Department of Astronomy
2011/12 - 2018/03

National Astronomical Observatory of Japan　Division of Theoretical Astronomy
2010/04 - 2011/11

The University of Tokyo
2009/10 - 2010/03

The University of Tokyo

Education 3

The University of Tokyo

2007/04 - 2009/09
The University of Tokyo

2005/04 - 2007/03
The University of Tokyo　Faculty of Science　Department of Astronomy

2001/04 - 2005/03

Committee Memberships 12

国立天文台科学戦略委員会委員

2018/10 - Present
TMT Science Advisory Committee (SAC)

2018/04 - Present
Convener of Time Domain Science, TMT international science development team

2013/07 - Present
国立天文台 TMT科学諮問委員会委員

2018/09 - 2022/08
国立天文台 CfCA科学諮問委員会委員

2018/10 - 2020/09
高エネルギー宇宙物理連絡会将来計画検討委員外部委員

2018/10 - 2020/09
国立天文台すばる科学諮問委員会委員

2018/09 - 2020/08
国立天文台 TMT推進小委員会委員

2013/04 - 2018/08
国立天文台すばる小委員会委員

2014/09 - 2018/07
国立天文台研究交流委員会委員

2016/07 - 2018/06
理論天文学宇宙物理学懇談会(理論懇) 運営委員

2015/12 - 2017/11
国立天文台計算機運用小委員会委員

2014/10 - 2016/09

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Professional Memberships 2

国際天文学連合
THE ASTRONOMICAL SOCIETY OF JAPAN

Research Interests 5

天文学
重力波
中性子星
超新星爆発
宇宙物理学

Research Areas 1

Natural sciences / Astronomy /

Awards 9

令和2年度古在由秀賞

2021/03　天文学振興財団
第17回日本学術振興会賞

2020/12　日本学術振興会
科学技術分野の文部科学大臣表彰科学技術賞

2019/04　文部科学省
Young Astronomer Lectureship Award

2017/10　NCU-DELTA
第8回井上リサーチアウォード

2017/02　井上科学振興財団
科学技術分野の文部科学大臣表彰若手科学者賞

2016/04　文部科学省
研究奨励賞

2016/03　日本天文学会
第28回井上研究奨励賞

2012/02　井上科学振興財団
総長賞

2010/03　東京大学

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Papers 242

Thorium in Kilonova Spectra: Exploring the Heaviest Detectable Element

Nanae Domoto, Shinya Wanajo, Masaomi Tanaka, Daiji Kato, Kenta Hotokezaka

ASTROPHYSICAL JOURNAL　978　(1)　2025/01/01

DOI： 10.3847/1538-4357/ad96b3 　

ISSN： 0004-637X

eISSN： 1538-4357
Three dimensional end-to-end simulation for kilonova emission from a black hole neutron star merger

Kyohei Kawaguchi, Nanae Domoto, Sho Fujibayashi, Hamid Hamidani, Kota Hayashi, Masaru Shibata, Masaomi Tanaka, Shinya Wanajo

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY　535　(4)　3711-3731　2024/12/03

DOI： 10.1093/mnras/stae2594 　

ISSN： 0035-8711

eISSN： 1365-2966
GRB 211211A: The Case for an Engine-powered over r-process-powered Blue Kilonova

Hamid Hamidani, Masaomi Tanaka, Shigeo S. Kimura, Gavin P. Lamb, Kyohei Kawaguchi

The Astrophysical Journal Letters　971　(2)　L30-L30　2024/08/01
Publisher: American Astronomical Society
DOI： 10.3847/2041-8213/ad6864 　

ISSN： 2041-8205

eISSN： 2041-8213

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Abstract The recent gamma-ray burst (GRB) GRB 211211A provides the earliest (∼5 hr) data of a kilonova (KN) event, displaying bright (∼10⁴² erg s⁻¹) and blue early emission. Previously, this KN was explained using simplistic multicomponent fitting methods. Here, in order to understand the physical origin of the KN emission in GRB 211211A, we employ an analytic multizone model for r-process-powered KNe. We find that r-process-powered KN models alone cannot explain the fast temporal evolution and the spectral energy distribution (SED) of the observed emission. Specifically, (i) r-process models require high ejecta mass to match early luminosity, which overpredicts late-time emission, while (ii) red KN models that reproduce late emission underpredict early luminosity. We propose an alternative scenario involving early contributions from the GRB central engine via a late low-power jet, consistent with plateau emission in short GRBs and GeV emission detected by Fermi-LAT at ∼10⁴ s after GRB 211211A. Such late central engine activity, with an energy budget of ∼a few percent of that of the prompt jet, combined with a single red KN ejecta component, can naturally explain the light curve and SED of the observed emission, with the late-jet–ejecta interaction reproducing the early blue emission and r-process heating reproducing the late red emission. This supports claims that late low-power engine activity after prompt emission may be common. We encourage early follow-up observations of future nearby GRBs and compact binary merger events to reveal more about the central engine of GRBs and r-process events.
Compensation of defective pixels by mechanical shift of an NIR array detector used in the NINJA echelle spectrograph

Kenshi Yanagisawa, Chihiro Tokoku, Kentaro Motohara, Shinobu Ozaki, Yoshito Ono, Yosuke Minowa, Takashi Moriya, Masami Ouchi, Nozomu Tominaga, Masayuki Tanaka, Yutaka Hayano, Yusei Koyama, Sadman Shariar Ali, Masaomi Tanaka, Masayuki Akiyama, Tohru Nagao, Yoshiki Matsuoka, Kosuke Kushibiki, Shogo Homan, Akino Yasuda, Tomoya Yukino, Riku Sato, Kensho Tanaka, Tomoyasu Yamamuro, Michitoshi Yoshida

Ground-based and Airborne Instrumentation for Astronomy X　2024/07/18
Publisher: SPIE
DOI： 10.1117/12.3016873 　
Optical Variability of Blazars in the Tomo-e Gozen Northern Sky Transient Survey

TianFang Zhang, Mamoru Doi, Mitsuru Kokubo, Shigeyuki Sako, Ryou Ohsawa, Nozomu Tominaga, Masaomi Tanaka, Yasushi Fukazawa, Hidenori Takahashi, Noriaki Arima, Naoto Kobayashi, Ko Arimatsu, Shin-ichiro Okumura, Sohei Kondo, Toshihiro Kasuga, Yuki Mori, Yuu Niino

The Astrophysical Journal　968　(2)　71-71　2024/06/01
Publisher: American Astronomical Society
DOI： 10.3847/1538-4357/ad4292 　

ISSN： 0004-637X

eISSN： 1538-4357

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Abstract We studied the optical variability of 241 BL Lacertae (BL Lacs) and 83 flat-spectrum radio quasars (FSRQs) from the 4LAC catalog using data from the Tomo-e Gozen Northern Sky Transient Survey, with ∼50 epochs per blazar on average. We excluded blazars whose optical variability may be underestimated due to the influence of their host galaxy based on their optical luminosity (L _O). FSRQs with γ-ray photon index greater than 2.6 exhibit very low optical variability, and their distribution of standard deviation of repeated photometry is significantly different from that of the other FSRQs (Kolmogorov–Smirnov test p-value equal to 5 × 10⁻⁶). Among a sample of blazars at any particular cosmological epoch, those with lower γ-ray luminosity (L _γ) tend to have lower optical variability, and those FSRQs with a γ-ray photon index greater than 2.6 tend to have low L _γ. We also measured the structure function of optical variability and found that the amplitude of the structure function for FSRQs is higher than previously measured and higher than that of BL Lacs at multiple time lags. Additionally, the amplitude of the structure function of FSRQs with high γ-ray photon index is significantly lower than that of FSRQs with low γ-ray photon index. The structure function of FSRQs of high γ-ray photon index shows a characteristic timescale of more than 10 days, which may be the variability timescale of the accretion disk. In summary, we infer that the optical component of FSRQs with high γ-ray photon index may be dominated by the accretion disk.
Diversity of Early Kilonova with the Realistic Opacities of Highly Ionized Heavy Elements

Smaranika Banerjee, Masaomi Tanaka, Daiji Kato, Gediminas Gaigalas

The Astrophysical Journal　968　(2)　64-64　2024/06/01
Publisher: American Astronomical Society
DOI： 10.3847/1538-4357/ad4029 　

ISSN： 0004-637X

eISSN： 1538-4357

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Abstract We investigate early (t < 1 day) kilonova from a neutron star merger by deriving atomic opacities for all the elements from La to Ra (Z = 57–88) ionized to the states V–XI. The opacities at high temperatures for the elements with open f-shells (e.g., lanthanides) are exceptionally high, reaching at λ ≤ 1000 Å at T ∼ 70,000 K, whereas the opacities at the same temperature and wavelengths for the elements with open d-, p-, and s-shells reach , 0.1, and 0.01 cm² g⁻¹, respectively. Using the new opacity data set, we derive early kilonovae for various compositions and density structures expected for neutron star merger ejecta. The bolometric luminosity of the lanthanide-rich ejecta shows distinct signatures and is fainter than that of the lanthanide-free ejecta. Early luminosity is suppressed by the presence of a thin outer layer, agreeing with the results of Kasen et al. and Banerjee et al. The early brightness in the Swift UVOT filters and in the optical g, r, i, and z filters for a source at 100 Mpc are about ∼22–19.5 and ∼21–20 mag, respectively, at t ∼ 0.1 day. Such kilonovae are ideal targets for the upcoming UV satellites, such as ULTRASAT, UVEX, and DORADO, and the upcoming surveys, e.g., the Vera Rubin Observatory. We suggest that the gray opacities that reproduce the bolometric light curves with and without lanthanides are ∼1–10 and ∼0.8 cm² g⁻¹.
Theoretical investigation of energy levels and transitions for Ce <scp>iii</scp> with applications to kilonova spectra

G Gaigalas, P Rynkun, N Domoto, M Tanaka, D Kato, L Kitovienė

Monthly Notices of the Royal Astronomical Society　530　(4)　5220-5227　2024/05/03
Publisher: Oxford University Press (OUP)
DOI： 10.1093/mnras/stae1196 　

ISSN： 0035-8711

eISSN： 1365-2966

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ABSTRACT Doubly ionized cerium (Ce2+) is one of the most important ions to understand the kilonova spectra. In particular, near-infrared (NIR) transitions of Ce iii between the ground (5p6 4f2) and first excited (5p6 4f 5d) configurations are responsible for the absorption features around 14 500 Å. However, there is no dedicated theoretical studies to provide accurate transition probabilities for these transitions. We present energy levels of the ground and first excited configurations and transition data between them for Ce iii. Calculations are performed using the grasp2018 package, which is based on the multiconfiguration Dirac–Hartree–Fock and relativistic configuration interaction methods. Compared with the energy levels in the NIST data base (Kramida et al. 2024), our calculations reach the accuracy with the root-mean-square (rms) of 2732 or 1404 cm−1 (excluding one highest level) for ground configuration, and rms of 618 cm−1 for the first excited configuration. We extensively study the line strengths and find that the Babushkin gauge provides the more accurate values. By using the calculated gf values, we show that the NIR spectral features of kilonova can be explained by the Ce iii lines.
On the Formation of the W-shaped O ii Lines in Spectra of Type I Superluminous Supernovae

Sei Saito, Masaomi Tanaka, Paolo A. Mazzali, Stephan Hachinger, Kenta Hotokezaka

The Astrophysical Journal　967　(1)　13-13　2024/05/01
Publisher: American Astronomical Society
DOI： 10.3847/1538-4357/ad39e8 　

ISSN： 0004-637X

eISSN： 1538-4357

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Abstract H-poor Type I superluminous supernovae (SLSNe I) are characterized by O ii lines around 4000–4500 Å in pre-/near-maximum spectra, the so-called W-shaped O ii lines. As these lines are from relatively high excitation levels, they have been considered a sign of nonthermal processes, which may provide a hint of the power sources of SLSNe I. However, the conditions for these lines to appear have not been well understood. In this work, we systematically calculate synthetic spectra to reproduce the observed spectra of eight SLSNe I, parameterizing departure coefficients from the nebular approximation in the supernova ejecta (expressed as b _neb). We find that most of the observed spectra can be well reproduced with b _neb ≲ 10, which means that no strong departure is necessary for the formation of the W-shaped O ii lines. We also show that the appearance of the W-shaped O ii lines is sensitive to temperature; only spectra with temperatures in the range of T ∼ 14,000–16,000 K can produce the W-shaped O ii lines without large departures. Based on this, we constrain the nonthermal ionization rate near the photosphere. Our results suggest that spectral features of SLSNe I can give independent constraints on the power source through the nonthermal ionization rates.
Measurement of transition probabilities of La II using Laser Induced Breakdown Spectroscopy (LIBS)

Kodangil Supriya, Nanae Domoto, Masaomi Tanaka, Daiji Kato, Gediminas Gaigalas, Hajime Tanuma, Nobuyuki Nakamura

Journal of Quantitative Spectroscopy and Radiative Transfer　109011-109011　2024/04
Publisher: Elsevier BV
DOI： 10.1016/j.jqsrt.2024.109011 　

ISSN： 0022-4073
Abundance stratification in type Ia supernovae – VII. The peculiar, C-rich iPTF16abc: highlighting diversity among luminous events

Charles J Aouad, Paolo A Mazzali, Chris Ashall, Masaomi Tanaka, Stephan Hachinger

Monthly Notices of the Royal Astronomical Society　529　(4)　3838-3857　2024/03/23
Publisher: Oxford University Press (OUP)
DOI： 10.1093/mnras/stae785 　

ISSN： 0035-8711

eISSN： 1365-2966

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ABSTRACT Observations of Type Ia supernovae (SNe Ia) reveal diversity, even within assumed subcategories. Here, the composition of the peculiar iPTF16abc (SN 2016bln) is derived by modelling a time series of optical spectra. iPTF16abc’s early spectra combine traits of SNe 1999aa and 1991T known for weak Si ii λ 6355 and prominent Fe iii features. However, it differs with weak early Fe iii lines, and persistent C ii lines post-peak. It also exhibits a weak Ca ii H&K feature aligning it with SN 1991T, an observation supported by their bolometric light curves. The early attenuation of Fe iii results from abundance effect. The weakening of the Si ii λ 6355 line, stems from silicon depletion in the outer shells, a characteristic shared by both SNe 1999aa and 1991T, indicating a common explosion mechanism that terminates nuclear burning at around 12 000 km s−1 unseen in normal events. Beneath a thin layer of intermediate mass elements (IMEs) with a total mass of 0.18 M⊙, extends a 56Ni rich shell totaling 0.76 M⊙ and generating a bolometric luminosity as high as Lpeak = 1.60 ± 0.1 × 1043 ergs s−1. Inner layers, typical of SNe Ia, hold neutron-rich elements, (54Fe and 58Ni), totaling 0.20 M⊙. Stable iron, exceeding solar abundance, and carbon, coexist in the outermost layers, challenging existing explosion models. The presence of carbon down to v ≈ 9000 km s−1, totalling ∼0.01 M⊙ unprecedented in this class, links iPTF16abc to SN 2003fg-like events. The retention of 91T-like traits in iPTF16abc underscores its importance in understanding the diversity of SNe Ia.
Red supergiant candidates for multimessenger monitoring of the next Galactic supernova

Sarah Healy, Shunsaku Horiuchi, Marta Colomer Molla, Dan Milisavljevic, Jeff Tseng, Faith Bergin, Kathryn Weil, Masaomi Tanaka, Sebastián Otero

Monthly Notices of the Royal Astronomical Society　529　(4)　3630-3650　2024/03/15
Publisher: Oxford University Press (OUP)
DOI： 10.1093/mnras/stae738 　

ISSN： 0035-8711

eISSN： 1365-2966

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ABSTRACT We compile a catalogue of 578 highly probable and 62 likely red supergiants (RSGs) of the Milky Way, which represents the largest list of Galactic RSG candidates designed for continuous follow-up efforts to date. We match distances measured by Gaia DR3, 2MASS photometry, and a 3D Galactic dust map to obtain luminous bright late-type stars. Determining the stars’ bolometric luminosities and effective temperatures, we compare to Geneva stellar evolution tracks to determine likely RSG candidates, and quantify contamination using a catalogue of Galactic AGB in the same luminosity-temperature space. We add details for common or interesting characteristics of RSG, such as multistar system membership, variability, and classification as a runaway. As potential future core-collapse supernova progenitors, we study the ability of the catalogue to inform the Supernova Early Warning System (SNEWS) coincidence network made to automate pointing, and show that for 3D position estimates made possible by neutrinos, the number of progenitor candidates can be significantly reduced, improving our ability to observe the progenitor pre-explosion and the early phases of core-collapse supernovae.
Late Engine Activity in Neutron Star Mergers and Its Cocoon: An Alternative Scenario for the Blue Kilonova

Hamid Hamidani, Shigeo S. Kimura, Masaomi Tanaka, Kunihito Ioka

The Astrophysical Journal　963　(2)　137-137　2024/03/01
Publisher: American Astronomical Society
DOI： 10.3847/1538-4357/ad20d0 　

ISSN： 0004-637X

eISSN： 1538-4357

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Abstract Follow-up observations of short gamma-ray bursts (sGRBs) have continuously unveiled late extended/plateau emissions, attributed to jet launch due to late engine activity, the nature of which remains enigmatic. Observations of GW170817 have confirmed that sGRBs are linked to neutron star (NS) mergers, and discovered a kilonova (KN) transient. Nevertheless, the origin of the early blue KN in GW170817 remains unclear. Here, we investigate the propagation of late jets in the merger ejecta. By analytically modeling jet dynamics, we determine the properties of the jet-heated cocoon, and estimate its cooling emission. Our results reveal that late jets generate significantly brighter cocoons compared to prompt jets, primarily due to reduced energy loss by adiabatic cooling. Notably, with typical late jets, emission from the cocoon trapped inside the ejecta can reproduce the blue KN emission. We estimate that the forthcoming Einstein Probe mission will detect the early cocoon emission at a rate of $\sim {2.1}_{-1.6}^{+3.2}$ yr⁻¹, and that optical/UV follow-ups in the LIGO-Virgo-KAGRA O5 run will be able to detect $\sim {1.0}_{-0.7}^{+1.5}$ cocoon emission events. As an electromagnetic counterpart, this emission provides an independent tool to probe NS mergers in the Universe, complementing insights from sGRBs and gravitational waves.
Intermediate-luminosity Type IIP SN 2021gmj: a low-energy explosion with signatures of circumstellar material

Yuta Murai, Masaomi Tanaka, Miho Kawabata, Kenta Taguchi, Rishabh Singh Teja, Tatsuya Nakaoka, Keiichi Maeda, Koji S Kawabata, Takashi Nagao, Takashi J Moriya, D K Sahu, G C Anupama, Nozomu Tominaga, Tomoki Morokuma, Ryo Imazawa, Satoko Inutsuka, Keisuke Isogai, Toshihiro Kasuga, Naoto Kobayashi, Sohei Kondo, Hiroyuki Maehara, Yuki Mori, Yuu Niino, Mao Ogawa, Ryou Ohsawa, Shin-ichiro Okumura, Sei Saito, Shigeyuki Sako, Hidenori Takahashi, Kohki Uno, Masayuki Yamanaka

Monthly Notices of the Royal Astronomical Society　528　(3)　4209-4227　2024/01/16
Publisher: Oxford University Press (OUP)
DOI： 10.1093/mnras/stae170 　

ISSN： 0035-8711

eISSN： 1365-2966

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ABSTRACT We present photometric, spectroscopic, and polarimetric observations of the intermediate-luminosity Type IIP supernova (SN) 2021gmj from 1 to 386 d after the explosion. The peak absolute V-band magnitude of SN 2021gmj is −15.5 mag, which is fainter than that of normal Type IIP SNe. The spectral evolution of SN 2021gmj resembles that of other sub-luminous SNe: The optical spectra show narrow P-Cygni profiles, indicating a low expansion velocity. We estimate the progenitor mass to be about 12 $\rm {\rm M}_{\odot}$ from the nebular spectrum and the 56Ni mass to be about 0.02 $\rm {\rm M}_{\odot}$ from the bolometric light curve. We also derive the explosion energy to be about 3 × 1050 erg by comparing numerical light-curve models with the observed light curves. Polarization in the plateau phase is not very large, suggesting nearly spherical outer envelope. The early photometric observations capture the rapid rise of the light curve, which is likely due to the interaction with a circumstellar material (CSM). The broad emission feature formed by highly ionized lines on top of a blue continuum in the earliest spectrum gives further indication of the CSM at the vicinity of the progenitor. Our work suggests that a relatively low-mass progenitor of an intermediate-luminosity Type IIP SN can also experience an enhanced mass-loss just before the explosion, as suggested for normal Type IIP SNe.
A New Insight into Electron Acceleration Properties from Theoretical Modeling of Double-peaked Radio Light Curves in Core-collapse Supernovae

Tomoki Matsuoka, Shigeo S. Kimura, Keiichi Maeda, Masaomi Tanaka

The Astrophysical Journal　960　(1)　70-70　2023/12/27
Publisher: American Astronomical Society
DOI： 10.3847/1538-4357/ad096c 　

ISSN： 0004-637X

eISSN： 1538-4357

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Abstract It is recognized that some core-collapse supernovae (SNe) show a double-peaked radio light curve within a few years since the explosion. A shell of circumstellar medium (CSM) detached from the SN progenitor has been considered to play a viable role in characterizing such a rebrightening of radio emission. Here, we propose another mechanism that can give rise to the double-peaked radio light curve in core-collapse SNe. The key ingredient in the present work is to expand the model for the evolution of the synchrotron spectral energy distribution (SED) to a generic form, including fast and slow cooling regimes, as guided by the widely accepted modeling scheme of gamma-ray burst afterglows. We show that even without introducing an additional CSM shell, the radio light curve would show a double-peaked morphology when the system becomes optically thin to synchrotron self-absorption at the observational frequency during the fast cooling regime. We can observe this double-peaked feature if the transition from the fast cooling to slow cooling regime occurs during the typical observational timescale of SNe. This situation is realized when the minimum Lorentz factor of injected electrons is initially large enough for the nonthermal electrons’ SED to be discrete from the thermal distribution. We propose SN 2007bg as a special case of double-peaked radio SNe that can be possibly explained by the presented scenario. Our model can serve as a potential diagnostic for electron acceleration properties in SNe.
Bridging between Type IIb and Ib Supernovae: SN IIb 2022crv with a Very Thin Hydrogen Envelope

Anjasha Gangopadhyay, Keiichi Maeda, Avinash Singh, Nayana A. J., Tatsuya Nakaoka, Koji S. Kawabata, Kenta Taguchi, Mridweeka Singh, Poonam Chandra, Stuart D. Ryder, Raya Dastidar, Masayuki Yamanaka, Miho Kawabata, Rami Z. E. Alsaberi, Naveen Dukiya, Rishabh Singh Teja, Bhavya Ailawadhi, Anirban Dutta, D. K. Sahu, Takashi J. Moriya, Kuntal Misra, Masaomi Tanaka, Roger Chevalier, Nozomu Tominaga, Kohki Uno, Ryo Imazawa, Taisei Hamada, Tomoya Hori, Keisuke Isogai

The Astrophysical Journal　957　(2)　100-100　2023/11/01
Publisher: American Astronomical Society
DOI： 10.3847/1538-4357/acfa94 　

ISSN： 0004-637X

eISSN： 1538-4357

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Abstract We present optical, near-infrared, and radio observations of supernova (SN) SN IIb 2022crv. We show that it retained a very thin H envelope and transitioned from an SN IIb to an SN Ib; prominent Hα seen in the pre-maximum phase diminishes toward the post-maximum phase, while He i lines show increasing strength. SYNAPPS modeling of the early spectra of SN 2022crv suggests that the absorption feature at 6200 Å is explained by a substantial contribution of Hα together with Si ii, as is also supported by the velocity evolution of Hα. The light-curve evolution is consistent with the canonical stripped-envelope SN subclass but among the slowest. The light curve lacks the initial cooling phase and shows a bright main peak (peak M _V = −17.82 ± 0.17 mag), mostly driven by radioactive decay of ⁵⁶Ni. The light-curve analysis suggests a thin outer H envelope (M _env ∼ 0.05 M _⊙) and a compact progenitor (R _env ∼ 3 R _⊙). An interaction-powered synchrotron self-absorption model can reproduce the radio light curves with a mean shock velocity of 0.1c. The mass-loss rate is estimated to be in the range of (1.9−2.8) × 10⁻⁵ M _⊙ yr⁻¹ for an assumed wind velocity of 1000 km s⁻¹, which is on the high end in comparison with other compact SNe IIb/Ib. SN 2022crv fills a previously unoccupied parameter space of a very compact progenitor, representing a beautiful continuity between the compact and extended progenitor scenario of SNe IIb/Ib.
A search for extragalactic fast optical transients in the Tomo-e Gozen high-cadence survey

Kakeru Oshikiri, Masaomi Tanaka, Nozomu Tominaga, Tomoki Morokuma, Ichiro Takahashi, Yusuke Tampo, Hamid Hamidani, Noriaki Arima, Ko Arimatsu, Toshihiro Kasuga, Naoto Kobayashi, Sohei Kondo, Yuki Mori, Yuu Niino, Ryou Ohsawa, Shin-ichiro Okumura, Shigeyuki Sako, Hidenori Takahashi

Monthly Notices of the Royal Astronomical Society　527　(1)　334-345　2023/10/28
Publisher: Oxford University Press (OUP)
DOI： 10.1093/mnras/stad3184 　

ISSN： 0035-8711

eISSN： 1365-2966

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ABSTRACT The population of optical transients evolving within a time-scale of a few hours or a day (so-called fast optical transients, FOTs) has recently been debated extensively. In particular, our understanding of extragalactic FOTs and their rates is limited. We present a search for extragalactic FOTs with the Tomo-e Gozen high-cadence survey. Using the data taken from 2019 August to 2022 June, we obtain 113 FOT candidates. Through light curve analysis and cross-matching with other survey data, we find that most of these candidates are in fact supernovae, variable quasars, and Galactic dwarf novae that were partially observed around their peak brightness. We find no promising candidate of extragalactic FOTs. From this non-detection, we obtain upper limits on the event rate of extragalactic FOTs as a function of their time-scale. For a very luminous event (absolute magnitude M &lt; −26 mag), we obtain the upper limits of 4.4 × 10−9 Mpc−3 yr−1 for a time-scale of 4 h, and 7.4 × 10−10 Mpc−3 yr−1 for a time-scale of 1 d. Thanks to our wide (although shallow) surveying strategy, our data are less affected by the cosmological effects, and thus, give one of the more stringent limits to the event rate of intrinsically luminous transients with a time-scale of &lt;1 d.
Transition Probabilities of Near-infrared Ce iii Lines from Stellar Spectra: Applications to Kilonovae

Nanae Domoto, Jae-Joon Lee, Masaomi Tanaka, Ho-Gyu Lee, Wako Aoki, Miho N. Ishigaki, Shinya Wanajo, Daiji Kato, Kenta Hotokezaka

The Astrophysical Journal　956　(2)　113-113　2023/10/01
Publisher: American Astronomical Society
DOI： 10.3847/1538-4357/acf65a 　

ISSN： 0004-637X

eISSN： 1538-4357

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Abstract Kilonova spectra provide us with information of r-process nucleosynthesis in neutron star mergers. However, it is still challenging to identify individual elements in the spectra mainly due to the lack of experimentally accurate atomic data for heavy elements at near-infrared wavelengths. Recently, Domoto et al. proposed that the absorption features around 14500 Å in the observed spectra of GW170817/AT2017gfo are Ce iii lines. But they used theoretical transition probabilities (gf-values) whose accuracy is uncertain. In this paper, we derive the astrophysical gf-values of three Ce iii lines, aiming at verifying this identification. We model high-resolution H-band spectra of four F-type supergiants showing clear Ce iii absorption features by assuming stellar parameters derived from optical spectra in the literature. We also test the validity of the derived astrophysical gf-values by estimating the Ce iii abundances of Ap stars. We find that the derived astrophysical gf-values of the Ce iii lines are systematically lower by about 0.25 dex than those used in previous work of kilonovae, while they are still compatible within the uncertainty ranges. By performing radiative transfer simulations of kilonovae with the derived gf-values, we find that the identification of Ce iii as a source of absorption features in the observed kilonova spectra still stands, even considering the uncertainties in the astrophysical gf-values. This supports the identification of Ce in the spectra of GW170817/AT2017gfo.
Cerium Features in Kilonova Near-infrared Spectra: Implication from a Chemically Peculiar Star

Masaomi Tanaka, Nanae Domoto, Wako Aoki, Miho N. Ishigaki, Shinya Wanajo, Kenta Hotokezaka, Kyohei Kawaguchi, Daiji Kato, Jae-Joon Lee, Ho-Gyu Lee, Teruyuki Hirano, Takayuki Kotani, Masayuki Kuzuhara, Jun Nishikawa, Masashi Omiya, Motohide Tamura, Akitoshi Ueda

The Astrophysical Journal　953　(1)　17-17　2023/07/28
Publisher: American Astronomical Society
DOI： 10.3847/1538-4357/acdc95 　

ISSN： 0004-637X

eISSN： 1538-4357

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Abstract Observations of the kilonova from the neutron star merger event GW170817 opened a way to study r-process nucleosynthesis directly using neutron star mergers. It is, however, challenging to identify individual elements in kilonova spectra due to a lack of complete atomic data, in particular at near-infrared (NIR) wavelengths. In this paper, we demonstrate that spectra of chemically peculiar stars with enhanced heavy-element abundances can provide us with an excellent astrophysical laboratory for kilonova spectra. We show that the photosphere of the late B-type, chemically peculiar star HR 465 has similar lanthanide abundances and ionization degrees with those in the line-forming region in a kilonova at ∼2.5 days after the merger. The NIR spectrum of HR 465 taken with Subaru/IRD indicates that Ce iii lines give the strongest absorption feature around 16000 Å and there are no other comparably strong transitions around these lines. The Ce iii lines nicely match with the broad absorption feature at 14500 Å observed in GW170817 with a blueshift of v = 0.1 c, which supports recent identification of this feature as Ce iii by Domoto et al.
Follow-up Survey for the Binary Black Hole Merger GW200224_222234 Using Subaru/HSC and GTC/OSIRIS

Takayuki Ohgami, Josefa Becerra González, Nozomu Tominaga, Tomoki Morokuma, Yousuke Utsumi, Yuu Niino, Masaomi Tanaka, Smaranika Banerjee, Frédérick Poidevin, Jose Antonio Acosta-Pulido, Ismael Pérez-Fournon, Teo Muñoz-Darias, Hiroshi Akitaya, Kenshi Yanagisawa, Mahito Sasada, Michitoshi Yoshida, Mirko Simunovic, Ryou Ohsawa, Ichi Tanaka, Tsuyoshi Terai, Yuhei Takagi

The Astrophysical Journal　947　(1)　9-9　2023/04/01
Publisher: American Astronomical Society
DOI： 10.3847/1538-4357/acbd42 　

ISSN： 0004-637X

eISSN： 1538-4357

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Abstract The LIGO/Virgo detected a gravitational wave (GW) event, named GW200224_222234 (also known as S200224ca) and classified as a binary-black hole coalescence, on 2020 February 24. Given its relatively small localization skymap (71 deg² for a 90% credible region; revised to 50 deg² in GWTC-3), we performed target-of-opportunity observations using the Subaru/Hyper Suprime-Cam (HSC) in the r2 and z bands. Observations were conducted on 2020 February 25 and 28 and March 23, with the first epoch beginning 12.3 hr after the GW detection. The survey covered the highest-probability sky area of 56.6 deg², corresponding to a 91% probability. This was the first deep follow-up (m_r ≳ 24, m_z ≳ 23) for a binary-black hole merger covering >90% of the localization. By performing image subtraction and candidate screening including light-curve fitting with transient templates and examples, we found 22 off-nucleus transients that were not ruled out as the counterparts of GW200224_222234 with our Subaru/HSC data alone. We also performed GTC/OSIRIS spectroscopy of the probable host galaxies for five candidates; two are likely to be located within the 3D skymap, whereas the others are not. In conclusion, 19 transients remain as possible optical counterparts of GW200224_222234; but we could not identify a unique promising counterpart. If there are no counterparts in the remaining candidates, the upper limits of the optical luminosity are $\nu {L}_{\nu }\lt {5.2}_{-1.9}^{+2.4}\times {10}^{41}$ erg s⁻¹ and $\nu {L}_{\nu }\lt {1.8}_{-0.6}^{+0.8}\times {10}^{42}$ erg s⁻¹ in the r2 and z bands, respectively, at ∼12 hr after GW detection. We also discuss improvements in the strategies of optical follow-ups for future GW events.
Charge Exchange Spectroscopy of Multiply Charged Erbium Ions

Yuki Nishimura, Saki Imaizumi, Hajime Tanuma, Nobuyuki Nakamura, Yuichiro Sekiguchi, Shinya Wanajo, Hiroyuki A. Sakaue, Daiji Kato, Izumi Murakami, Masaomi Tanaka, Gediminas Gaigalas

Atoms　11　(2)　40-40　2023/02/15
Publisher: MDPI AG
DOI： 10.3390/atoms11020040 　

eISSN： 2218-2004

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The origin of heavier elements than iron is still under discussion, and recent studies suggest that the contribution of the r-process in neutron star mergers is dominant. Future modeling of such processes will require a huge amount of spectroscopic data on multiply charged ions of heavy elements. However, these experimental data are extremely scarce for heavy elements. In this work, we have performed the measurements of charge exchange spectroscopy for multiply charged Er ions in the visible light range. We report observed emission lines from multiply charged Er ions and their identification based on theoretical estimates.
SN 2020uem: a Possible Thermonuclear Explosion within a Dense Circumstellar Medium (II). The Properties of the CSM from Polarimetry and Light-curve Modeling

Kohki Uno, Takashi Nagao, Keiichi Maeda, Hanindyo Kuncarayakti, Masaomi Tanaka, Koji S. Kawabata, Tatsuya Nakaoka, Miho Kawabata, Masayuki Yamanaka, Kentaro Aoki, Keisuke Isogai, Mao Ogawa, Akito Tajitsu, Ryo Imazawa

The Astrophysical Journal　944　(2)　204-204　2023/02/01
Publisher: American Astronomical Society
DOI： 10.3847/1538-4357/acb5eb 　

ISSN： 0004-637X

eISSN： 1538-4357

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Abstract Type IIn/Ia-CSM supernovae (SNe IIn/Ia-CSM) are classified by their characteristic spectra, which exhibit narrow hydrogen emission lines originating from strong interaction with a circumstellar medium (CSM) together with broad lines of intermediate-mass elements. We performed intensive follow-up observations of SN IIn/Ia-CSM 2020uem, including photometry, spectroscopy, and polarimetry. In this paper, we focus on the results of polarimetry. We performed imaging polarimetry at 66 days and spectropolarimetry at 103 days after discovery. SN 2020uem shows a high continuum polarization of 1.0%–1.5% without wavelength dependence. Besides, the polarization degree and position angle keep roughly constant. These results suggest that SN 2020uem is powered by strong interaction with a confined and aspherical CSM. We performed simple polarization modeling, based on which we suggest that SN 2020uem has an equatorial-disk/torus CSM. Besides, we performed semi-analytic light-curve modeling and estimated the CSM mass. We revealed that the mass-loss rate in the final few hundred years immediately before the explosion of SN 2020uem is in the range of 0.01–0.05 M_⊙ yr⁻¹, and that the total CSM mass is 0.5–4 M_⊙. The CSM mass can be accommodated by not only a red supergiant (RSG), but also by a red giant (RG) or an asymptotic giant branch (AGB) star. As a possible progenitor scenario of SN 2020uem, we propose a white dwarf binary system including an RG, RSG, or AGB star, especially a merger scenario via common envelope evolution, i.e., the core-degenerate scenario or a variant.
SN 2020uem: a Possible Thermonuclear Explosion within a Dense Circumstellar Medium. I. The Nature of Type IIn/Ia-CSM SNe from Photometry and Spectroscopy

Kohki Uno, Keiichi Maeda, Takashi Nagao, Tatsuya Nakaoka, Kentaro Motohara, Akito Tajitsu, Masahiro Konishi, Shuhei Koyama, Hidenori Takahashi, Masaomi Tanaka, Hanindyo Kuncarayakti, Miho Kawabata, Masayuki Yamanaka, Kentaro Aoki, Keisuke Isogai, Kenta Taguchi, Mao Ogawa, Koji S. Kawabata, Yuzuru Yoshii, Takashi Miyata, Ryo Imazawa

The Astrophysical Journal　944　(2)　203-203　2023/02/01
Publisher: American Astronomical Society
DOI： 10.3847/1538-4357/acb5ec 　

ISSN： 0004-637X

eISSN： 1538-4357

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Abstract We have performed intensive follow-up observations of a Type IIn/Ia-CSM supernova (SN IIn/Ia-CSM), 2020uem, with photometry, spectroscopy, and polarimetry. In this paper, we report on the results of our observations focusing on optical/near-infrared (NIR) photometry and spectroscopy. The maximum V-band magnitude of SN 2020uem is less than −19.5 mag. The light curves decline slowly with a rate of ∼0.75 mag/100 days. In the late phase (≳300 days), the light curves show accelerated decay (∼1.2 mag/100 days). The optical spectra show prominent hydrogen emission lines and broad features possibly associated with Fe-peak elements. In addition, the Hα profile exhibits a narrow P-Cygni profile with an absorption minimum of ∼100 km s⁻¹. SN 2020uem shows a higher Hα/Hβ ratio (∼7) than those of SNe IIn, which suggests a denser circumstellar medium (CSM). The NIR spectrum shows the Paschen and Brackett series with a continuum excess in the H and Ks bands. We conclude that the NIR excess emission originates from newly formed carbon dust. The dust mass (M_d) and temperature (T_d) are derived to be (M_d, T_d) ∼ (4−7 × 10⁻⁵M_⊙, 1500–1600 K). We discuss the differences and similarities between the observational properties of SNe IIn/Ia-CSM and those of other SNe Ia and interacting SNe. In particular, spectral features around ∼4650 Å and ∼5900 Å of SNe IIn/Ia-CSM are more suppressed than those of SNe Ia; these lines are possibly contributed, at least partly, by Mg i] and Na i, and may be suppressed by high ionization behind the reverse shock caused by the massive CSM.
Lanthanide Features in Near-infrared Spectra of Kilonovae

Nanae Domoto, Masaomi Tanaka, Daiji Kato, Kyohei Kawaguchi, Kenta Hotokezaka, Shinya Wanajo

The Astrophysical Journal　939　(1)　8-8　2022/10/26
Publisher: American Astronomical Society
DOI： 10.3847/1538-4357/ac8c36 　

ISSN： 0004-637X

eISSN： 1538-4357

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Abstract The observations of GW170817/AT2017gfo have provided us with evidence that binary neutron star mergers are sites of r-process nucleosynthesis. However, the observed signatures in the spectra of GW170817/AT2017gfo have not been fully decoded, especially in the near-infrared (NIR) wavelengths. In this paper, we investigate the kilonova spectra over the entire wavelength range with the aim of elemental identification. We systematically calculate the strength of bound–bound transitions by constructing a hybrid line list that is accurate for important strong transitions and complete for weak transitions. We find that the elements on the left side of the periodic table, such as Ca, Sr, Y, Zr, Ba, La, and Ce, tend to produce prominent absorption lines in the spectra. This is because such elements have a small number of valence electrons and low-lying energy levels, resulting in strong transitions. By performing self-consistent radiative transfer simulations for the entire ejecta, we find that La iii and Ce iii appear in the NIR spectra, which can explain the absorption features at λ ∼ 12000–14000 Å in the spectra of GW170817/AT2017gfo. The mass fractions of La and Ce are estimated to be >2 × 10⁻⁶ and ∼(1–100) × 10⁻⁵, respectively. An actinide element Th can also be a source of absorption as the atomic structure is analogous to that of Ce. However, we show that Th iii features are less prominent in the spectra because of the denser energy levels of actinides compared to those of lanthanides.
Euclid: Searching for pair-instability supernovae with the Deep Survey

T. J. Moriya, C. Inserra, M. Tanaka, E. Cappellaro, M. Della Valle, I. Hook, R. Kotak, G. Longo, F. Mannucci, S. Mattila, C. Tao, B. Altieri, A. Amara, N. Auricchio, D. Bonino, E. Branchini, M. Brescia, J. Brinchmann, S. Camera, V. Capobianco, C. Carbone, J. Carretero, M. Castellano, S. Cavuoti, A. Cimatti, R. Cledassou, G. Congedo, C. J. Conselice, L. Conversi, Y. Copin, L. Corcione, F. Courbin, M. Cropper, A. Da Silva, H. Degaudenzi, M. Douspis, F. Dubath, C. A. J. Duncan, X. Dupac, S. Dusini, A. Ealet, S. Farrens, S. Ferriol, M. Frailis, E. Franceschi, M. Fumana, B. Garilli, W. Gillard, B. Gillis, C. Giocoli, A. Grazian, F. Grupp, S. V. H. Haugan, W. Holmes, F. Hormuth, A. Hornstrup, K. Jahnke, S. Kermiche, A. Kiessling, M. Kilbinger, T. Kitching, H. Kurki-Suonio, S. Ligori, P. B. Lilje, I. Lloro, E. Maiorano, O. Mansutti, O. Marggraf, K. Markovic, F. Marulli, R. Massey, H. J. McCracken, M. Melchior, M. Meneghetti, G. Meylan, M. Moresco, L. Moscardini, E. Munari, S. M. Niemi, C. Padilla, S. Paltani, F. Pasian, K. Pedersen, V. Pettorino, M. Poncet, L. Popa, F. Raison, J. Rhodes, G. Riccio, E. Rossetti, R. Saglia, B. Sartoris, P. Schneider, A. Secroun, G. Seidel, C. Sirignano, G. Sirri, L. Stanco, P. Tallada-Crespí, A. N. Taylor, I. Tereno, R. Toledo-Moreo, F. Torradeflot, Y. Wang, G. Zamorani, J. Zoubian, S. Andreon, V. Scottez, P. W. Morris

Astronomy & Astrophysics　666　A157-A157　2022/10/20
Publisher: EDP Sciences
DOI： 10.1051/0004-6361/202243810 　

ISSN： 0004-6361

eISSN： 1432-0746

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Pair-instability supernovae are theorized supernovae that have not yet been observationally confirmed. They are predicted to exist in low-metallicity environments. Because overall metallicity becomes lower at higher redshifts, deep near-infrared transient surveys probing high-redshift supernovae are suitable to discover pair-instability supernovae. The Euclid satellite, which is planned launch in 2023, has a near-infrared wide-field instrument that is suitable for a high-redshift supernova survey. The Euclid Deep Survey is planned to make regular observations of three Euclid Deep Fields (40 deg² in total) spanning Euclid’s six-year primary mission period. While the observations of the Euclid Deep Fields are not frequent, we show that the predicted long duration of pair-instability supernovae would allow us to search for high-redshift pair-instability supernovae with the Euclid Deep Survey. Based on the current observational plan of the Euclid mission, we conduct survey simulations in order to estimate the expected numbers of pair-instability supernova discoveries. We find that up to several hundred pair-instability supernovae at z ≲ 3.5 can be discovered within the Euclid Deep Survey. We also show that pair-instability supernova candidates can be efficiently identified by their duration and color, which can be determined with the current Euclid Deep Survey plan. We conclude that the Euclid mission can lead to the first confirmation of pair-instability supernovae if their event rates are as high as those predicted by recent theoretical studies. We also update the expected numbers of superluminous supernova discoveries in the Euclid Deep Survey based on the latest observational plan.
Identifying High-energy Neutrino Transients by Neutrino Multiplet-triggered Follow-ups

Shigeru Yoshida, Kohta Murase, Masaomi Tanaka, Nobuhiro Shimizu, Aya Ishihara

The Astrophysical Journal　937　(2)　108-108　2022/10/01
Publisher: American Astronomical Society
DOI： 10.3847/1538-4357/ac8dfd 　

ISSN： 0004-637X

eISSN： 1538-4357

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Abstract Transient sources such as supernovae (SNe) and tidal disruption events are candidates of high-energy neutrino sources. However, SNe commonly occur in the universe and a chance coincidence of their detection with a neutrino signal cannot be avoided, which may lead to a challenge of claiming their association with neutrino emission. In order to overcome this difficulty, we propose a search for ∼10–100 TeV multiple neutrino events within a timescale of ∼30 days coming from the same direction, called neutrino multiplets. We show that demanding multiplet detection by a ∼1 km³ neutrino telescope limits the distances of detectable neutrino sources, which enables us to identify source counterparts by multiwavelength observations owing to the substantially reduced rate of the chance coincidence detection of transients. We apply our results by constructing a feasible strategy for optical follow-up observations and demonstrate that wide-field optical telescopes with a ≳4 m dish should be capable of identifying a transient associated with a neutrino multiplet. We also present the resultant sensitivity of multiplet neutrino detection as a function of the released energy of neutrinos and burst rate density. A model of neutrino transient sources with an emission energy greater than a few × 10⁵¹ erg and a burst rate rarer than a few ×10⁻⁸ Mpc⁻³ yr⁻¹ is constrained by the null detection of multiplets by a ∼1 km³ scale neutrino telescope. This already disfavors the canonical high-luminosity gamma-ray bursts and jetted tidal disruption events as major sources in the TeV-energy neutrino sky.
Theoretical investigation of energy levels and transitions for Pr <scp>iv</scp>

G Gaigalas, P Rynkun, S Banerjee, M Tanaka, D Kato, L Radžiūtė

Monthly Notices of the Royal Astronomical Society　517　(1)　281-293　2022/09/01
Publisher: Oxford University Press (OUP)
DOI： 10.1093/mnras/stac2401 　

ISSN： 0035-8711

eISSN： 1365-2966

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ABSTRACT We present extensive energy levels (1110 levels) and transition data for the Pr iv. We also show the effect of such atomic data on opacity for neutron star (NS) merger. We performed energy spectra and transition data calculations using the GRASP2018 package, which is based on the multiconfiguration Dirac–Hartree–Fock and relativistic configuration interaction methods. Using the GRASP2018 data, the opacities in the NS merger ejecta containing pure Pr are calculated. Energy levels are compared with recommended values from the NIST Atomic Spectra Database and other available works. Furthermore, electric dipole (E1) transition data, line strengths, weighted oscillator strengths, and transition rates are computed between the above levels. We estimate the uncertainties of the computed line strengths giving the accuracy class. The computed line strengths are also compared with other theoretical computations. We proposed few ways to estimate the uncertainties of the line strengths of the E1 transitions. Our calculation for opacity for a typical condition of NS merger ejecta at t ∼ 1 d shows that the Planck mean opacity of Pr3 + reaches $\sim 1\, \rm cm^{2}\, g^{-1}$ at $T\, \sim \, 15000$ K. The opacity is higher than that by the previous studies, thanks to the higher completeness of the atomic data. We also highlight the importance of accurate atomic data for the opacity by comparing it with the opacity using the atomic calculation from HULLAC. Moreover, we identify the important configurations, especially for the transitions between the high-lying levels for the opacity of 3+ ionized lanthanides.
NINJA : an LTAO assisted optical and near-infrared spectrograph of Subaru Telescope

Chihiro Tokoku, Shinobu Ozaki, Takashi Moriya, Kenshi Yanagisawa, Kentaro Motohara, Masami Ouchi, Nozomu Tominaga, Masaomi Tanaka, Yoshito Ono, Yosuke Minowa, Yutaka Hayano, Yusei Koyama, Sadman Ali, Masayuki Tanaka, Masayuki Akiyama, Tohru Nagao, Yoshiki Matsuoka, Kosuke Kushibiki, Shogo Homan, Akino Yasuda, Michitoshi Yoshida

Ground-based and Airborne Instrumentation for Astronomy IX　2022/08/29
Publisher: SPIE
DOI： 10.1117/12.2627749 　
Deep-learning real/bogus classification for the Tomo-e Gozen transient survey

Ichiro Takahashi, Ryo Hamasaki, Naonori Ueda, Masaomi Tanaka, Nozomu Tominaga, Shigeyuki Sako, Ryou Ohsawa, Naoki Yoshida

Publications of the Astronomical Society of Japan　74　(4)　946-960　2022/08/04
Publisher: Oxford University Press (OUP)
DOI： 10.1093/pasj/psac047 　

ISSN： 0004-6264

eISSN： 2053-051X

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Abstract We present a deep neural network real/bogus classifier that improves classification performance in the Tomo-e Gozen Transient survey by handling label errors in the training data. In the wide-field, high-frequency transient survey with Tomo-e Gozen, the performance of conventional convolutional neural network classifiers is not sufficient as about 106 bogus detections appear every night. In need of a better classifier, we have developed a new two-stage training method. In this training method, label errors in the training data are first detected by normal supervised learning classification, and then they are unlabeled and used for training of semi-supervised learning. For actual observed data, the classifier with this method achieves an area under the curve (AUC) of 0.9998 and a false positive rate (FPR) of 0.0002 at a true positive rate (TPR) of 0.9. This training method saves relabeling effort by humans and works better on training data with a high fraction of label errors. By implementing the developed classifier in the Tomo-e Gozen pipeline, the number of transient candidates was reduced to ∼40 objects per night, which is ∼1/130 of the previous version, while maintaining the recovery rate of real transients. This enables more efficient selection of targets for follow-up observations.
Video observations of tiny near-Earth objects with Tomo-e Gozen

Jin Beniyama, Shigeyuki Sako, Ryou Ohsawa, Satoshi Takita, Naoto Kobayashi, Shin Ichiro Okumura, Seitaro Urakawa, Makoto Yoshikawa, Fumihiko Usui, Fumi Yoshida, Mamoru Doi, Yuu Niino, Toshikazu Shigeyama, Masaomi Tanaka, Nozomu Tominaga, Tsutomu Aoki, Noriaki Arima, Ko Arimatsu, Toshihiro Kasuga, Sohei Kondo, Yuki Mori, Hidenori Takahashi, Jun Ichi Watanabe

Publications of the Astronomical Society of Japan　74　(4)　877-903　2022/08/01

DOI： 10.1093/pasj/psac043 　

ISSN： 0004-6264

eISSN： 2053-051X
Tungsten versus Selenium as a potential source of kilonova nebular emission observed by Spitzer

Kenta Hotokezaka, Masaomi Tanaka, Daiji Kato, Gediminas Gaigalas

Monthly Notices of the Royal Astronomical Society: Letters　515　(1)　L89-L93　2022/07/29
Publisher: Oxford University Press (OUP)
DOI： 10.1093/mnrasl/slac071 　

ISSN： 1745-3925

eISSN： 1745-3933

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ABSTRACT Infrared emission lines arising from transitions between fine structure levels of heavy elements are expected to produce kilonova nebular emission. For the kilonova in GW170817, strong emission at $4.5\, {\rm \mu m}$ at late times was detected by the Spitzer Space Telescope but no source was detected at $3.6\, {\rm \mu m}$. This peculiar spectrum indicates that strong line emitters exist around $4.5\, {\rm \mu m}$ and the absence of strong lines around $3.6\, {\rm \mu m}$. To model the spectrum we prepare a line list based on the selection rules in LS coupling from the experimentally calibrated energy levels in the NIST database. This method enables to generate the synthetic spectra with accurate line wavelengths. We find that the spectrum is sensitive to the abundance pattern whether or not the first r-process peak elements are included. In both cases, the synthetic spectra can match the observed data, leading to two possible interpretations. If the first peak elements are abundant, a Se iii line dominates the flux. If otherwise, W iii with Os iii, Rh iii, and Ce iv can be the main sources. Observing nebular spectra for the future kilonova in a wider wavelength range can provide more conclusive elemental identification.
Opacity of the Highly Ionized Lanthanides and the Effect on the Early Kilonova

Smaranika Banerjee, Masaomi Tanaka, Daiji Kato, Gediminas Gaigalas, Kyohei Kawaguchi, Nanae Domoto

The Astrophysical Journal　934　(2)　117-117　2022/07/29
Publisher: American Astronomical Society
DOI： 10.3847/1538-4357/ac7565 　

ISSN： 0004-637X

eISSN： 1538-4357

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Abstract We investigate the effect of the presence of lanthanides (Z = 57–71) on the kilonova at t ∼ 1 hr after the neutron star merger for the first time. For this purpose, we calculate the atomic structures and the opacities for selected lanthanides: Nd (Z = 60), Sm (Z = 62), and Eu (Z = 63). We consider the ionization degree up to 10th (XI), applicable for the ejecta at t ∼ a few hours after the merger, when the temperature is T ∼ 10⁵ K. We find that the opacities for the highly ionized lanthanides are exceptionally high, reaching ${\kappa }_{\exp }\sim 1000\,{\mathrm{cm } }^{2}\,{ { \rm{g } } }^{-1}$ for Eu, due to the highly dense energy levels. Using the new opacity, we perform radiative transfer simulations to show that the early light curves become fainter by a (maximum) factor of four, in comparison to lanthanide-free ejecta at t ∼ 0.1 days. However, the period at which the light curves are affected is relatively brief owing to the rapid time evolution of the opacity in the outermost layer of the ejecta. We predict that for a source at a distance of ∼100 Mpc, UV brightness for lanthanide-rich ejecta shows a drop to ∼21–22 mag at t ∼ 0.1 days and the UV peaks around t ∼ 0.2 days with a magnitude of ∼19 mag. Future detection of such a kilonova by an existing UV satellite like Swift or the upcoming UV satellite ULTRASAT will provide useful constraints on the abundance in the outer ejecta and the corresponding nucleosynthesis conditions in the neutron star mergers.
Abundance stratification in Type Ia supernovae – VI. The peculiar slow decliner SN 1999aa

Charles J Aouad, Paolo A Mazzali, Stephan Hachinger, Jacob Teffs, Elena Pian, Chris Ashall, Stefano Benetti, Alexei V Filippenko, Masaomi Tanaka

Monthly Notices of the Royal Astronomical Society　515　(3)　4445-4463　2022/07/27
Publisher: Oxford University Press (OUP)
DOI： 10.1093/mnras/stac2024 　

ISSN： 0035-8711

eISSN： 1365-2966

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ABSTRACT The abundance distribution in the ejecta of the peculiar slowly declining Type Ia supernova (SN Ia) SN 1999aa is obtained by modelling a time series of optical spectra. Similar to SN 1991T, SN 1999aa was characterized by early-time spectra dominated by Fe iii features and a weak Si ii 6355 Å line, but it exhibited a high-velocity Ca ii H&K line and morphed into a spectroscopically normal SN Ia earlier. Three explosion models are investigated, yielding comparable fits. The innermost layers are dominated by ∼0.3 M⊙ of neutron-rich stable iron-group elements, mostly stable iron. Above that central region lies a 56Ni-dominated shell, extending to $v \approx 11\, 000$–$12\, 000$ km s−1, with mass ∼0.65 M⊙. These inner layers are therefore similar to those of normal SNe Ia. However, the outer layers exhibit composition peculiarities similar to those of SN 1991T: The intermediate-mass elements shell is very thin, containing only ∼0.2 M⊙, and is sharply separated from an outer oxygen-dominated shell, which includes ∼0.22 M⊙. These results imply that burning suddenly stopped in SN 1999aa. This is a feature SN 1999aa shares with SN 1991T, and explains the peculiarities of both SNe, which are quite similar in nature apart from the different luminosities. The spectroscopic path from normal to SN 1991T-like SNe Ia cannot be explained solely by a temperature sequence. It also involves composition layering differences, suggesting variations in the progenitor density structure or in the explosion parameters.
MUSSES2020J: The Earliest Discovery of a Fast Blue Ultraluminous Transient at Redshift 1.063

Ji-an Jiang, Naoki Yasuda, Keiichi Maeda, Nozomu Tominaga, Mamoru Doi, Željko Ivezić, Peter Yoachim, Kohki Uno, Takashi J. Moriya, Brajesh Kumar, Yen-Chen Pan, Masayuki Tanaka, Masaomi Tanaka, Ken’ichi Nomoto, Saurabh W. Jha, Pilar Ruiz-Lapuente, David Jones, Toshikazu Shigeyama, Nao Suzuki, Mitsuru Kokubo, Hisanori Furusawa, Satoshi Miyazaki, Andrew J. Connolly, D. K. Sahu, G. C. Anupama

The Astrophysical Journal Letters　2022/07/01

DOI： 10.3847/2041-8213/ac7390 　
Deep Simultaneous Limits on Optical Emission from FRB 20190520B by 24.4 fps Observations with Tomo-e Gozen

Yuu Niino, Mamoru Doi, Shigeyuki Sako, Ryou Ohsawa, Noriaki Arima, Ji-an Jiang, Nozomu Tominaga, Masaomi Tanaka, Di Li, Chen-Hui Niu, Chao-Wei Tsai, Naoto Kobayashi, Hidenori Takahashi, Sohei Kondo, Yuki Mori, Tsutomu Aoki, Ko Arimatsu, Toshihiro Kasuga, Shin-ichiro Okumura

ASTROPHYSICAL JOURNAL　931　(2)　2022/06

DOI： 10.3847/1538-4357/ac6be8 　

ISSN： 0004-637X

eISSN： 1538-4357
Constraints on the Explosion Timescale of Core-collapse Supernovae Based on Systematic Analysis of Light Curves

Sei Saito, Masaomi Tanaka, Ryo Sawada, Takashi J. Moriya

The Astrophysical Journal　931　(2)　153-153　2022/06/01
Publisher: American Astronomical Society
DOI： 10.3847/1538-4357/ac6bec 　

ISSN： 0004-637X

eISSN： 1538-4357

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Abstract The explosion mechanism of core-collapse supernovae is not fully understood yet. In this work, we give constraints on the explosion timescale based on ⁵⁶Ni synthesized by supernova explosions. First, we systematically analyze multiband light curves of 82 stripped-envelope supernovae (SESNe) to obtain bolometric light curves, which is among the largest samples of the bolometric light curves of SESNe derived from the multiband spectral energy distribution. We measure the decline timescale and the peak luminosity of the light curves and estimate the ejecta mass (M_ej) and ⁵⁶Ni mass (M_Ni) to connect the observed properties with the explosion physics. We then carry out one-dimensional hydrodynamics and nucleosynthesis calculations, varying the progenitor mass and the explosion timescale. From the calculations, we show that the maximum ⁵⁶Ni mass that ⁵⁶Ni-powered SNe can reach is expressed as M_Ni ≲ 0.2 M_ej. Comparing the results from the observations and the calculations, we show that the explosion timescale shorter than 0.3 s explains the synthesized ⁵⁶Ni mass of the majority of the SESNe.
Statistical Properties of the Nebular Spectra of 103 Stripped-envelope Core-collapse Supernovae*

Qiliang Fang, Keiichi Maeda, Hanindyo Kuncarayakti, Masaomi Tanaka, Koji S. Kawabata, Takashi Hattori, Kentaro Aoki, Takashi J. Moriya, Masayuki Yamanaka

The Astrophysical Journal　928　(2)　151-151　2022/04/01
Publisher: American Astronomical Society
DOI： 10.3847/1538-4357/ac4f60 　
Laser Induced Breakdown Spectroscopy of Er II for Transition Probability Measurements

Yuki Naoi, Masayuki Iwata, Daichi Yokota, Gediminas Gaigalas, Daiji Kato, Izumi Murakami, Hiroyuki Sakaue, Yuichiro Sekiguchi, Masaomi Tanaka, Hajime Tanuma, Shinya Wanajo, Nobuyuki Nakamura

Applied Sciences　12　(4)　2219-2219　2022/02/21
Publisher: MDPI AG
DOI： 10.3390/app12042219 　

eISSN： 2076-3417

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We present a laser induced breakdown spectrum of Er II in the near ultraviolet region. To use the spectrum for the evaluation of the transition probabilities, an alloy target with a low content of Er was used to suppress the self-absorption. From the linearity of the Boltzmann plot obtained by using the sensitivity corrected experimental intensity and existing transition probability data, the local thermal equilibrium condition of the plasma and the reliability of the transition probability data are confirmed. The linear function obtained in the Boltzmann plot is used for the determination of a previously unreported transition probability for the line at 393.863 nm.
Theoretical investigation of energy levels and transition for Ce IV

P. Rynkun, S. Banerjee, G. Gaigalas, M. Tanaka, L. Radžiūtė, D. Kato

Astronomy & Astrophysics　658　A82-A82　2022/02
Publisher: EDP Sciences
DOI： 10.1051/0004-6361/202141513 　

ISSN： 0004-6361

eISSN： 1432-0746

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Aims. We present extensive energy level and transition data for the Ce IV spectrum. By providing accurate atomic data, we evaluate the impact of atomic data on the opacity in the neutron star merger ejecta. Methods. We performed energy spectra and transition data calculations using the GRASP2018 package, which is based on the multiconfiguration Dirac–Hartree–Fock and relativistic configuration interaction methods, and the HULLAC code, which is based on a parametric potential method. Results. We present energy spectra calculated for the 225 levels for the Ce³⁺ ion. Energy levels are compared with recommended values from the NIST Atomic Spectra Database and other available works. The root-mean-square (rms) deviations obtained for the GRASP2018 energy levels of the 5p⁶nl configurations from the NIST data are 1270 cm⁻¹. The rms deviations for the HULLAC results from the NIST data are 5780 cm⁻¹. Furthermore, electric dipole (E1) transition data, line strengths, weighted oscillator strengths, and transition rates are computed between the above levels. The computed transition rates are compared with other theoretical computations. We also evaluate the accuracy of the wave functions and transition parameters by analyzing the dependencies of the line strength S on the gauge parameter G. The gauge dependency method also allows us to determine the transitions for which the ratio between the Babushkin and Coulomb gauges shows real agreement between forms and the transitions for which the agreement between both gauges is random. Using the GRASP2018 and HULLAC data, the opacities in the neutron star merger ejecta are also calculated. We find that the opacity of Ce IV is higher than that presented by previous works, which is because of the higher completeness of our atomic data. Although the differences in the energy levels and transition probabilities cause different features in the opacity spectrum, the Planck mean opacities of both data sets agree within 20%.
Extended Calculations of Energy Levels and Transition Rates for Singly Ionized Lanthanide Elements. II. Tb−Yb

Laima Radžiūtė, Gediminas Gaigalas, Daiji Kato, Pavel Rynkun, Masaomi Tanaka

The Astrophysical Journal Supplement Series　257　(2)　29-29　2021/12/01
Publisher: American Astronomical Society
DOI： 10.3847/1538-4365/ac1ad2 　

ISSN： 0067-0049

eISSN： 1538-4365

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Abstract In this work, we continue large-scale ab initio computations for single ionized lanthanides. Extended atomic calculations for the set of ions from Pr ii (Z = 59) to Gd ii (Z = 64) have been performed in our previous work. In this study, ions from Tb ii (Z = 65) to Yb ii (Z = 70) are analyzed. By employing the same multiconfiguration Dirac–Hartree–Fock and relativistic configuration interaction methods that are implemented in the general-purpose relativistic atomic structure package GRASP2018, the energy levels and transition data of electric dipole (E1) transitions are computed. These computations are based on the strategies (with small variations) of Paper I. Accuracy of data is evaluated by comparing the computed energy levels with the data provided by the National Institute of Standards and Technology (NIST) database and with data from various methods. We obtain the average accuracy in the energy level compared with the NIST database: 6%, 5%, 4%, 5%, 3%, and 3% for Tb ii, Dy ii, Ho ii, Er ii, Tm ii, and Yb ii, respectively. We also provide extensive comparison of transition probabilities and wavelengths. Our results reach the average accuracy of transition wavelengths: 9%, 9%, 9%, 3%, 4%, and 11% for Tb ii, Dy ii, Ho ii, Er ii, Tm ii, and Yb ii, respectively.
Discovery of the Fastest Early Optical Emission from Overluminous SN Ia 2020hvf: A Thermonuclear Explosion within a Dense Circumstellar Environment

Ji-an Jiang, Keiichi Maeda, Miho Kawabata, Mamoru Doi, Toshikazu Shigeyama, Masaomi Tanaka, Nozomu Tominaga, Ken'ichi Nomoto, Yuu Niino, Shigeyuki Sako, Ryou Ohsawa, Malte Schramm, Masayuki Yamanaka, Naoto Kobayashi, Hidenori Takahashi, Tatsuya Nakaoka, Koji S. Kawabata, Keisuke Isogai, Tsutomu Aoki, Sohei Kondo, Yuki Mori, Ko Arimatsu, Toshihiro Kasuga, Shin-ichiro Okumura, Seitaro Urakawa, Daniel E. Reichart, Kenta Taguchi, Noriaki Arima, Jin Beniyama, Kohki Uno, Taisei Hamada

ASTROPHYSICAL JOURNAL LETTERS　923　(1)　2021/12

DOI： 10.3847/2041-8213/ac375f 　

ISSN： 2041-8205

eISSN： 2041-8213
Nebular emission from lanthanide-rich ejecta of neutron star merger

Kenta Hotokezaka, Masaomi Tanaka, Daiji Kato, Gediminas Gaigalas

Monthly Notices of the Royal Astronomical Society　506　5863-5877　2021/07

DOI： 10.1093/mnras/stab1975 　
A Low-mass Binary Neutron Star: Long-term Ejecta Evolution and Kilonovae with Weak Blue Emission Peer-reviewed

Kyohei Kawaguchi, Sho Fujibayashi, Masaru Shibata, Masaomi Tanaka, Shinya Wanajo

The Astrophysical Journal　913　(2)　100-100　2021/06/01

DOI： 10.3847/1538-4357/abf3bc 　

ISSN： 0004-637X

eISSN： 1538-4357
J-GEM optical and near-infrared follow-up of gravitational wave events during LIGO’s and Virgo’s third observing run Peer-reviewed

Mahito Sasada, Yousuke Utsumi, Ryosuke Itoh, Nozomu Tominaga, Masaomi Tanaka, Tomoki Morokuma, Kenshi Yanagisawa, Koji S Kawabata, Takayuki Ohgami, Michitoshi Yoshida, Fumio Abe, Ryo Adachi, Hiroshi Akitaya, Yang Chong, Kazuki Daikuhara, Ryo Hamasaki, Satoshi Honda, Ryohei Hosokawa, Kota Iida, Fumiya Imazato, Chihiro Ishioka, Takumi Iwasaki, Mingjie Jian, Yuhei Kamei, Takahiro Kanai, Hidehiro Kaneda, Ayane Kaneko, Noriyuki Katoh, Nobuyuki Kawai, Keiichiro Kubota, Yuma Kubota, Hideo Mamiya, Kazuya Matsubayashi, Kumiko Morihana, Katsuhiro L Murata, Takahiro Nagayama, Noriatsu Nakamura, Tatsuya Nakaoka, Yuu Niino, Yuki Nishinaka, Masafumi Niwano, Daisaku Nogami, Yumiko Oasa, Miki Oeda, Futa Ogawa, Ryou Ohsawa, Kouji Ohta, Kohei Oide, Hiroki Onozato, Shigeyuki Sako, Tomoki Saito, Yuichiro Sekiguchi, Toshikazu Shigeyama, Takumi Shigeyoshi, Minori Shikauchi, Kazuki Shiraishi, Daisuke Suzuki, Kengo Takagi, Jun Takahashi, Takuya Takarada, Masaki Takayama, Himeka Takeuchi, Yasuki Tamura, Ryoya Tanaka, Sayaka Toma, Miyako Tozuka, Nagomi Uchida, Yoshinori Uzawa, Masayuki Yamanaka, Moeno Yasuda, Yoichi Yatsu

Progress of Theoretical and Experimental Physics　2021　(5)　2021/05/18

DOI： 10.1093/ptep/ptab007 　

ISSN： 2050-3911

eISSN： 2050-3911
Signatures of r-process Elements in Kilonova Spectra Peer-reviewed

Nanae Domoto, Masaomi Tanaka, Shinya Wanajo, Kyohei Kawaguchi

The Astrophysical Journal　913　(1)　26-26　2021/05/01
Publisher: American Astronomical Society
DOI： 10.3847/1538-4357/abf358 　

ISSN： 0004-637X

eISSN： 1538-4357
Calcium-rich Transient SN 2019ehk in a Star-forming Environment: Yet Another Candidate for a Precursor of a Double Neutron-star Binary Peer-reviewed

Tatsuya Nakaoka, Keiichi Maeda, Masayuki Yamanaka, Masaomi Tanaka, Miho Kawabata, Takashi J. Moriya, Koji S. Kawabata, Nozomu Tominaga, Kengo Takagi, Fumiya Imazato, Tomoki Morokuma, Shigeyuki Sako, Ryou Ohsawa, Takashi Nagao, Ji-an Jiang, Umut Burgaz, Kenta Taguchi, Makoto Uemura, Hiroshi Akitaya, Mahito Sasada, Keisuke Isogai, Masaaki Otsuka, Hiroyuki Maehara

The Astrophysical Journal　912　(1)　30-30　2021/05/01
Publisher: American Astronomical Society
DOI： 10.3847/1538-4357/abe765 　

ISSN： 0004-637X

eISSN： 1538-4357
R-process enhancements of Gaia-Enceladus in GALAH DR3 Peer-reviewed

T. Matsuno, Y. Hirai, Y. Tarumi, K. Hotokezaka, M. Tanaka, A. Helmi

Astronomy & Astrophysics　650　2021/04/15

DOI： 10.1051/0004-6361/202040227 　

ISSN： 0004-6361

eISSN： 1432-0746
Gravitational wave physics and astronomy in the nascent era

Makoto Arimoto, Hideki Asada, Michael L Cherry, Michiko S Fujii, Yasushi Fukazawa, Akira Harada, Kazuhiro Hayama, Takashi Hosokawa, Kunihito Ioka, Yoichi Itoh, Nobuyuki Kanda, Koji S Kawabata, Kyohei Kawaguchi, Nobuyuki Kawai, Tsutomu Kobayashi, Kazunori Kohri, Yusuke Koshio, Kei Kotake, Jun Kumamoto, Masahiro N Machida, Hideo Matsufuru, Tatehiro Mihara, Masaki Mori, Tomoki Morokuma, Shinji Mukohyama, Hiroyuki Nakano, Tatsuya Narikawa, Hitoshi Negoro, Atsushi Nishizawa, Takayuki Ohgami, Kazuyuki Omukai, Takanori Sakamoto, Shigeyuki Sako, Mahito Sasada, Yuichiro Sekiguchi, Motoko Serino, Jiro Soda, Satoshi Sugita, Kohsuke Sumiyoshi, Hajime Susa, Teruaki Suyama, Hirotaka Takahashi, Kazuya Takahashi, Tomoya Takiwaki, Takahiro Tanaka, Masaomi Tanaka, Ataru Tanikawa, Nozomu Tominaga, Nami Uchikata, Yousuke Utsumi, Mark R Vagins, Kei Yamada, Michitoshi Yoshida

Progress of Theoretical and Experimental Physics　2021/04/08

DOI： 10.1093/ptep/ptab042 　

ISSN： 2050-3911

eISSN： 2050-3911
Optical follow-up observation for GW event S190510g using Subaru/Hyper Suprime-Cam Peer-reviewed

Takayuki Ohgami, Nozomu Tominaga, Yousuke Utsumi, Yuu Niino, Masaomi Tanaka, Smaranika Banerjee, Ryo Hamasaki, Michitoshi Yoshida, Tsuyoshi Terai, Yuhei Takagi, Tomoki Morokuma, Mahito Sasada, Hiroshi Akitaya, Naoki Yasuda, Kenshi Yanagisawa, Ryou Ohsawa

Publications of the Astronomical Society of Japan　73　(2)　350-364　2021/04/05
Publisher: Oxford University Press (OUP)
DOI： 10.1093/pasj/psab002 　

ISSN： 0004-6264

eISSN： 2053-051X

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<title>Abstract</title> A gravitational wave event, S190510g, which was classified as a binary-neutron-star coalescence at the time of preliminary alert, was detected by LIGO/Virgo collaboration on 2019 May 10. At 1.7 hours after the issue of its preliminary alert, we started a target-of-opportunity imaging observation in the Y band to search for its optical counterpart using the Hyper Suprime-Cam (HSC) on the Subaru Telescope. The observation covers a 118.8 deg2 sky area corresponding to $11.6\%$ confidence in the localization skymap released in the preliminary alert and $1.2\%$ in the updated skymap. We divided the observed area into two fields based on the availability of HSC reference images. For the fields with the HSC reference images, we applied an image subtraction technique; for the fields without the HSC reference images, we sought individual HSC images by matching a catalog of observed objects with the PS1 catalog. The search depth is 22.28 mag in the former method and the limit of search depth is 21.3 mag in the latter method. Subsequently, we performed visual inspection and obtained 83 candidates using the former method and 50 candidates using the latter method. Since we only have the one-day photometric data, we evaluated the probability of candidates being located inside the 3D skymap by estimating their distances with photometry of associated extended objects. We found three candidates are likely located inside the 3D skymap and concluded they could be a counterpart of S190510g, while most of the 133 candidates were likely to be supernovae because the number density of candidates was consistent with the expected number of supernova detections. By comparing our observational depth with a light-curve model of such a kilonova reproducing AT2017gfo, we show that early deep observations with the Subaru/HSC can capture the rising phase of the blue component of a kilonova at the estimated distance of S190510g (∼230 Mpc).
Follow-up observations for IceCube-170922A: Detection of rapid near-infrared variability and intensive monitoring of TXS 0506+056 Peer-reviewed

Tomoki Morokuma, Yousuke Utsumi, Kouji Ohta, Masayuki Yamanaka, Koji S Kawabata, Yoshiyuki Inoue, Masaomi Tanaka, Michitoshi Yoshida, Ryosuke Itoh, Mahito Sasada, Nozomu Tominaga, Hiroki Mori, Miho Kawabata, Tatsuya Nakaoka, Maiko Chogi, Taisei Abe, Ruochen Huang, Naoki Kawahara, Hiroki Kimura, Hiroki Nagashima, Kengo Takagi, Yuina Yamazaki, Wei Liu, Ryou Ohsawa, Shigeyuki Sako, Katsuhiro L Murata, Kumiko Morihana, Christina K Gilligan, Keisuke Isogai, Mariko Kimura, Yasuyuki Wakamatsu, Ryuhei Ohnishi, Masaki Takayama, Satoshi Honda, Yoshiki Matsuoka, Takuji Yamashita, Shigehiro Nagataki, Yasuyuki T Tanaka

Publications of the Astronomical Society of Japan　73　(1)　25-43　2021/02/05

DOI： 10.1093/pasj/psaa110 　

ISSN： 0004-6264

eISSN： 2053-051X
Polarized kilonovae from black hole-neutron star mergers Peer-reviewed

Bulla, M, Kyutoku, K, Tanaka, M, Covino, S, Bruten, J. R, Matsumoto, T, Maund, J. R, Testa, V, Wiersema, K

501　1891-1899　2021/02
Constraints on the Rate of Supernovae Lasting for More Than a Year from Subaru/Hyper Suprime-Cam Peer-reviewed

Takashi J. Moriya, Ji-an Jiang, Naoki Yasuda, Mitsuru Kokubo, Kojiro Kawana, Keiichi Maeda, Yen-Chen Pan, Robert M. Quimby, Nao Suzuki, Ichiro Takahashi, Masaomi Tanaka, Nozomu Tominaga, Ken’ichi Nomoto, Jeff Cooke, Lluís Galbany, Santiago González-Gaitán, Chien-Hsiu Lee, Giuliano Pignata

The Astrophysical Journal　908　(2)　249-249　2021/02/01
Publisher: American Astronomical Society
DOI： 10.3847/1538-4357/abcfc0 　

ISSN： 0004-637X

eISSN： 1538-4357

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Abstract Some supernovae, such as pair-instability supernovae, are predicted to have a duration of more than a year in the observer frame. To constrain the rates of supernovae lasting for more than a year, we conducted a long-term deep transient survey using Hyper Suprime-Cam (HSC) on the 8.2 m Subaru telescope. HSC is a wide-field (a 1.75 deg² field-of-view) camera and it can efficiently conduct transient surveys. We observed the same 1.75 deg² field repeatedly using the g-, r-, i-, and z-band filters with the typical depth of 26 mag for four seasons (from late 2016 to early 2020). Using these data, we searched for transients lasting for more than a year. Two supernovae were detected in two continuous seasons, one supernova was detected in three continuous seasons, but no transients lasted for all four seasons searched. The discovery rate of supernovae lasting for more than a year with the typical limiting magnitudes of 26 mag is constrained to be ${1.4}_{-0.7}^{+1.3}$$(\mathrm{stat}.){}_{-0.3}^{+0.2}(\mathrm{sys}.)\,\mathrm{events}\,{\deg }^{-2}\,{\mathrm{yr } }^{-1}$. All the long-lasting supernovae we found are likely Type IIn supernovae and our results indicate that about 40% of Type IIn supernovae have long-lasting light curves. No plausible pair-instability supernova candidates lasting for more than a year are discovered. By comparing the survey results and survey simulations, we constrain the luminous pair-instability supernova rate up to z ≃ 3 is of the order of 100 Gpc⁻³ yr⁻¹ at most, which is 0.01–0.1% of the core-collapse supernova rate.
Relationship between radar cross section and optical magnitude based on radar and optical simultaneous observations of faint meteors Peer-reviewed

Ryou Ohsawa, Akira Hirota, Kohei Morita, Shinsuke Abe, Daniel Kastinen, Johan Kero, Csilla Szasz, Yasunori Fujiwara, Takuji Nakamura, Koji Nishimura, Shigeyuki Sako, Jun-ichi Watanabe, Tsutomu Aoki, Noriaki Arima, Ko Arimatsu, Mamoru Doi, Makoto Ichiki, Shiro Ikeda, Yoshifusa Ita, Toshihiro Kasuga, Naoto Kobayashi, Mitsuru Kokubo, Masahiro Konishi, Hiroyuki Maehara, Takashi Miyata, Yuki Mori, Mikio Morii, Tomoki Morokuma, Kentaro Motohara, Yoshikazu Nakada, Shin-ichiro Okumura, Yuki Sarugaku, Mikiya Sato, Toshikazu Shigeyama, Takao Soyano, Hidenori Takahashi, Masaomi Tanaka, Ken’ichi Tarusawa, Nozomu Tominaga, Seitaro Urakawa, Fumihiko Usui, Takuya Yamashita, Makoto Yoshikawa

Planetary and Space Science　194　105011-105011　2020/12

DOI： 10.1016/j.pss.2020.105011 　

ISSN： 0032-0633
Photometric classification of Hyper Suprime-Cam transients using machine learning Peer-reviewed

Ichiro Takahashi, Nao Suzuki, Naoki Yasuda, Akisato Kimura, Naonori Ueda, Masaomi Tanaka, Nozomu Tominaga, Naoki Yoshida

Publications of the Astronomical Society of Japan　72　(5)　2020/10/02
Publisher: Oxford University Press (OUP)
DOI： 10.1093/pasj/psaa082 　

ISSN： 0004-6264

eISSN： 2053-051X

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<title>Abstract</title> The advancement of technology has resulted in a rapid increase in supernova (SN) discoveries. The Subaru/Hyper Suprime-Cam (HSC) transient survey, conducted from fall 2016 through spring 2017, yielded 1824 SN candidates. This gave rise to the need for fast type classification for spectroscopic follow-up and prompted us to develop a machine learning algorithm using a deep neural network with highway layers. This algorithm is trained by actual observed cadence and filter combinations such that we can directly input the observed data array without any interpretation. We tested our model with a dataset from the LSST classification challenge (Deep Drilling Field). Our classifier scores an area under the curve (AUC) of 0.996 for binary classification (SN Ia or non-SN Ia) and 95.3% accuracy for three-class classification (SN Ia, SN Ibc, or SN II). Application of our binary classification to HSC transient data yields an AUC score of 0.925. With two weeks of HSC data since the first detection, this classifier achieves 78.1% accuracy for binary classification, and the accuracy increases to 84.2% with the full dataset. This paper discusses the potential use of machine learning for SN type classification purposes.
Simulations of Early Kilonova Emission from Neutron Star Mergers Peer-reviewed

Smaranika Banerjee, Masaomi Tanaka, Kyohei Kawaguchi, Daiji Kato, Gediminas Gaigalas

The Astrophysical Journal　901　(1)　29-29　2020/09/18
Publisher: American Astronomical Society
DOI： 10.3847/1538-4357/abae61 　

eISSN： 1538-4357
Systematic opacity calculations for kilonovae Peer-reviewed

Masaomi Tanaka, Daiji Kato, Gediminas Gaigalas, Kyohei Kawaguchi

Monthly Notices of the Royal Astronomical Society　496　(2)　1369-1392　2020/08/01
Publisher: Oxford University Press (OUP)
DOI： 10.1093/mnras/staa1576 　

ISSN： 0035-8711

eISSN： 1365-2966

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<title>ABSTRACT</title>Coalescence of neutron stars (NSs) gives rise to kilonova, thermal emission powered by radioactive decays of freshly synthesized r-process nuclei. Although observational properties are largely affected by bound–bound opacities of r-process elements, available atomic data have been limited. In this paper, we study element-to-element variation of the opacities in the ejecta of NS mergers by performing systematic atomic structure calculations of r-process elements for the first time. We show that the distributions of energy levels tend to be higher as electron occupation increases for each electron shell due to the larger energy spacing caused by larger effects of spin–orbit and electron–electron interactions. As a result, elements with a fewer number of electrons in the outermost shells tend to give larger contributions to the bound–bound opacities. This implies that Fe is not representative for the opacities of light r-process elements. The average opacities for the mixture of r-process elements are found to be κ ∼ 20–30 cm2 g−1 for the electron fraction of Ye ≤ 0.20, κ ∼ 3–5 cm2 g−1 for Ye = 0.25–0.35, and κ ∼ 1 cm2 g−1 for Ye = 0.40 at $T = 5000\!-\!10\, 000$ K, and they steeply decrease at lower temperature. We show that, even with the same abundance or Ye, the opacity in the ejecta changes with time by one order of magnitude from 1 to 10 d after the merger. Our radiative transfer simulations with the new opacity data confirm that ejecta with a high electron fraction (Ye ≳ 0.25, with no lanthanide) are needed to explain the early, blue emission in GW170817/AT2017gfo while lanthanide-rich ejecta (with a mass fraction of lanthanides ∼5 × 10−3) reproduce the long-lasting near-infrared emission.
Energy levels structure of Pr II - Gd II ions

L. Radžiute, G. Gaigalas, P. Rynkun, D. Kato, M. Tanaka

Journal of Physics: Conference Series　1412　(13)　2020/06/11
Publisher: Institute of Physics Publishing
DOI： 10.1088/1742-6596/1412/13/132008 　

ISSN： 1742-6596 1742-6588
Late-phase Spectropolarimetric Observations of Superluminous Supernova SN 2017egm to Probe the Geometry of the Inner Ejecta Peer-reviewed

Sei Saito, Masaomi Tanaka, Takashi J. Moriya, Mattia Bulla, Giorgos Leloudas, Cosimo Inserra, Chien-Hsiu Lee, Koji S. Kawabata, Paolo Mazzali

The Astrophysical Journal　894　(2)　154-154　2020/05/18
Publisher: American Astronomical Society
DOI： 10.3847/1538-4357/ab873b 　

eISSN： 1538-4357
The intermediate nebular phase of SN 2014J: onset of clumping as the source of recombination Peer-reviewed

P A Mazzali, I Bikmaev, R Sunyaev, C Ashall, S Prentice, M Tanaka, E Irtuganov, S Melnikov, R Zhuchkov

Monthly Notices of the Royal Astronomical Society　494　(2)　2809-2822　2020/05/11
Publisher: Oxford University Press (OUP)
DOI： 10.1093/mnras/staa839 　

ISSN： 0035-8711

eISSN： 1365-2966

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<title>ABSTRACT</title> At the age of about 1 yr, the spectra of most Type Ia supernovae (SNe Ia) are dominated by strong forbidden nebular emission lines of Fe ii and Fe iii. Later observations (at about 2 yr) of the nearby SN 2011fe showed an unexpected shift of ionization to Fe i and Fe ii. Spectra of the very nearby SN Ia 2014J at an intermediate phase (1–1.5 yr) that are presented here show a progressive decline of Fe iii emission, while Fe i is not yet strong. The decrease in ionization can be explained if the degree of clumping in the ejecta increases significantly at ∼1.5 yr, at least in the Fe-dominated zone. Models suggest that clumps remain coherent after about one year, behaving like shrapnel. The high density in the clumps, combined with the decreasing heating rate, would then cause recombination. These data may witness the phase of transition from relatively smooth ejecta to the very clumpy morphology that is typical of SN remnants. The origin of the increased clumping may be the development of local magnetic fields.
Extended Calculations of Energy Levels and Transition Rates for Singly Ionized Lanthanide Elements. I. Pr–Gd Peer-reviewed

Laima Radžiūtė, Gediminas Gaigalas, Daiji Kato, Pavel Rynkun, Masaomi Tanaka

The Astrophysical Journal Supplement Series　248　(1)　17-17　2020/05/07
Publisher: American Astronomical Society
DOI： 10.3847/1538-4365/ab8312 　

eISSN： 1538-4365
Energy Level Structure and Transition Data of Er2+ Peer-reviewed

Gediminas Gaigalas, Pavel Rynkun, Laima Radžiūtė, Daiji Kato, Masaomi Tanaka, P. Jönsson

The Astrophysical Journal Supplement Series　248　(1)　13-13　2020/05/05
Publisher: American Astronomical Society
DOI： 10.3847/1538-4365/ab881a 　

eISSN： 1538-4365
Rapidly Evolving Transients from the Hyper Suprime-Cam SSP Transient Survey Peer-reviewed

Yusuke Tampo, Masaomi Tanaka, Keiichi Maeda, Naoki Yasuda, Nozomu Tominaga, Ji-an Jiang, Takashi J. Moriya, Tomoki Morokuma, Nao Suzuki, Ichiro Takahashi, Mitsuru Kokubo, Kojiro Kawana

The Astrophysical Journal　894　(1)　27-27　2020/05/01
Publisher: American Astronomical Society
DOI： 10.3847/1538-4357/ab7ccc 　

eISSN： 1538-4357
Constraint on the Ejecta Mass for Black Hole–Neutron Star Merger Event Candidate S190814bv Peer-reviewed

Kyohei Kawaguchi, Masaru Shibata, Masaomi Tanaka

The Astrophysical Journal　893　(2)　153-153　2020/04/27
Publisher: American Astronomical Society
DOI： 10.3847/1538-4357/ab8309 　

eISSN： 1538-4357
The HSC-SSP Transient Survey: Implications from Early Photometry and Rise Time of Normal Type Ia Supernovae

Ji-an Jiang, Naoki Yasuda, Keiichi Maeda, Mamoru Doi, Toshikazu Shigeyama, Nozomu Tominaga, Masaomi Tanaka, Takashi J. Moriya, Ichiro Takahashi, Nao Suzuki, Tomoki Morokuma, Ken’ichi Nomoto

The Astrophysical Journal　892　(1)　25-25　2020/03/23
Publisher: American Astronomical Society
DOI： 10.3847/1538-4357/ab76cb 　

eISSN： 1538-4357
On the Possibility of GW190425 Being a Black Hole–Neutron Star Binary Merger

Koutarou Kyutoku, Sho Fujibayashi, Kota Hayashi, Kyohei Kawaguchi, Kenta Kiuchi, Masaru Shibata, Masaomi Tanaka

The Astrophysical Journal　890　(1)　L4-L4　2020/02/06

DOI： 10.3847/2041-8213/ab6e70 　

ISSN： 2041-8205

eISSN： 2041-8213
Diversity of Kilonova Light Curves

Kyohei Kawaguchi, Masaru Shibata, Masaomi Tanaka

The Astrophysical Journal　889　(2)　171-171　2020/02/04

DOI： 10.3847/1538-4357/ab61f6 　

ISSN： 0004-637X

eISSN： 1538-4357
An optical search for transients lasting a few seconds Peer-reviewed

Michael W Richmond, Masaomi Tanaka, Tomoki Morokuma, Shigeyuki Sako, Ryou Ohsawa, Noriaki Arima, Nozomu Tominaga, Mamoru Doi, Tsutomu Aoki, Ko Arimatsu, Makoto Ichiki, Shiro Ikeda, Yoshifusa Ita, Toshihiro Kasuga, Koji S Kawabata, Hideyo Kawakita, Naoto Kobayashi, Mitsuru Kokubo, Masahiro Konishi, Hiroyuki Maehara, Hiroyuki Mito, Takashi Miyata, Yuki Mori, Mikio Morii, Kentaro Motohara, Yoshikazu Nakada, Shin-Ichiro Okumura, Hiroki Onozato, Yuki Sarugaku, Mikiya Sato, Toshikazu Shigeyama, Takao Soyano, Hidenori Takahashi, Ataru Tanikawa, Ken’ichi Tarusawa, Seitaro Urakawa, Fumihiko Usui, Junichi Watanabe, Takuya Yamashita, Makoto Yoshikawa

Publications of the Astronomical Society of Japan　72　(1)　3　2019/12/06
Publisher: Oxford University Press (OUP)
DOI： 10.1093/pasj/psz120 　

ISSN： 0004-6264

eISSN： 2053-051X

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<title>Abstract</title> Using a prototype of the Tomo-e Gozen wide-field CMOS mosaic camera, we acquire wide-field optical images at a cadence of $2\:$Hz and search them for transient sources of duration 1.5 to $11.5\:$s. Over the course of eight nights, our survey encompasses the equivalent of roughly two days on one square degree, to a fluence equivalent to a limiting magnitude of about $V = 15.6$ in a 1-s exposure. After examining by-eye the candidates identified by a software pipeline, we find no sources which meet all our criteria. We compute upper limits to the rate of optical transients consistent with our survey, and compare those to the rates expected and observed for representative sources of ephemeral optical light.
A Rapidly Declining Transient Discovered with the Subaru/Hyper Suprime-Cam Peer-reviewed

Tominaga Nozomu, Morokuma Tomoki, Tanaka Masaomi, Yasuda Naoki, Furusawa Hisanori, Tanaka Masayuki, Jiang Ji-an, Tolstov Alexey, Blinnikov Sergei, Doi Mamoru, Iwata Ikuru, Kuncarayakti Hanindyo, Moriya Takashi J, Nagao Tohru, Nomoto Ken'ichi, Noumaru Junichi, Takata Tadafumi

ASTROPHYSICAL JOURNAL　885　(1)　2019/11/01

DOI： 10.3847/1538-4357/ab425c 　

ISSN： 0004-637X
Short GRB 160821B: A Reverse Shock, a Refreshed Shock, and a Well-sampled Kilonova

G. P. Lamb, N. R. Tanvir, A. J. Levan, A. de Ugarte Postigo, K. Kawaguchi, A. Corsi, P. A. Evans, B. Gompertz, D. B. Malesani, K. L. Page, K. Wiersema, S. Rosswog, M. Shibata, M. Tanaka, A. J. van der Horst, Z. Cano, J. P. U. Fynbo, A. S. Fruchter, J. Greiner, K. E. Heintz, A. Higgins, J. Hjorth, L. Izzo, P. Jakobsson, D. A. Kann, P. T. O’Brien, D. A. Perley, E. Pian, G. Pugliese, R. L. C. Starling, C. C. Thöne, D. Watson, R. A. M. J. Wijers, D. Xu

The Astrophysical Journal　883　(1)　48-48　2019/09/19
Publisher: American Astronomical Society
DOI： 10.3847/1538-4357/ab38bb 　

eISSN： 1538-4357
HSC16aayt: A Slowly Evolving Interacting Transient Rising for More than 100 Days Peer-reviewed

Moriya Takashi J, Tanaka Masaomi, Morokuma Tomoki, Pan Yen-Chen, Quimby Robert M, Jiang Ji-an, Kawana Kojiro, Maeda Keiichi, Nomoto Ken'ichi, Suzuki Nao, Takahashi Ichiro, Tanaka Masayuki, Tominaga Nozomu, Yamaguchi Masaki, Yasuda Naoki, Cooke Jeff, Curtin Chris, Galbany Lluis, Gonzalez-Gaitan Santiago, Lee Chien-Hsiu, Pignata Giuliano, Pritchard Tyler

ASTROPHYSICAL JOURNAL　882　(1)　70-70　2019/09/01

DOI： 10.3847/1538-4357/ab2f80 　

ISSN： 0004-637X

eISSN： 1538-4357
GRB 161219B/SN 2016jca: a powerful stellar collapse

C Ashall, P A Mazzali, E Pian, S E Woosley, E Palazzi, S J Prentice, S Kobayashi, S Holmbo, A Levan, D Perley, M D Stritzinger, F Bufano, A V Filippenko, A Melandri, S Oates, A Rossi, J Selsing, W Zheng, A J Castro-Tirado, G Chincarini, P D’Avanzo, M De Pasquale, S Emery, A S Fruchter, K Hurley, P Moller, K Nomoto, M Tanaka, A F Valeev

Monthly Notices of the Royal Astronomical Society　487　(4)　5824-5839　2019/08/21
Publisher: Oxford University Press (OUP)
DOI： 10.1093/mnras/stz1588 　

ISSN： 0035-8711

eISSN： 1365-2966

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<title>ABSTRACT</title> We report observations and analysis of the nearby gamma-ray burst GRB 161219B (redshift z = 0.1475) and the associated Type Ic supernova (SN) 2016jca. GRB 161219B had an isotropic gamma-ray energy of ∼1.6 × 1050 erg. Its afterglow is likely refreshed at an epoch preceding the first photometric points (0.6 d), which slows down the decay rates. Combined analysis of the SN light curve and multiwavelength observations of the afterglow suggest that the GRB jet was broad during the afterglow phase (full opening angle ∼42° ± 3°). Our spectral series shows broad absorption lines typical of GRB supernovae (SNe), which testify to the presence of material with velocities up to ∼0.25c. The spectrum at 3.73 d allows for the very early identification of an SN associated with a GRB. Reproducing it requires a large photospheric velocity ($35\, 000 \pm 7000$ km s−1). The kinetic energy of the SN is estimated through models to be Ekin≈4 × 1052 erg in spherical symmetry. The ejected mass in the explosion was Mej≈6.5 ± 1.5 M⊙, much less than that of other GRB-SNe, demonstrating diversity among these events. The total amount of 56Ni in the explosion was 0.27 ± 0.05 M⊙. The observed spectra require the presence of freshly synthesized 56Ni at the highest velocities, at least three times more than a standard GRB-SN. We also find evidence for a decreasing 56Ni abundance as a function of decreasing velocity. This suggests that SN 2016jca was a highly aspherical explosion viewed close to on-axis, powered by a compact remnant. Applying a typical correction for asymmetry, the energy of SN 2016jca was ∼(1–3) × 1052 erg, confirming that most of the energy produced by GRB-SNe goes into the kinetic energy of the SN ejecta.
The Hyper Suprime-Cam SSP transient survey in COSMOS: Overview Peer-reviewed

Yasuda, Naoki, Tanaka, Masaomi, Tominaga, Nozomu, Jiang, Ji-an, Moriya, Takashi J, Morokuma, Tomoki, Suzuki, Nao, Takahashi, Ichiro, Yamaguchi, Masaki S, Maeda, Keiichi, Sako, Masao, Ikeda, Shiro, Kimura, Akisato, Morii, Mikio, Ueda, Naonori, Yoshida, Naoki, Lee, Chien-Hsiu, Suyu, Sherry H, Komiyama, Yutaka, Regnault, Nicolas, Rubin, David

Publications of the Astronomical Society of Japan　2019/08/01

DOI： 10.1093/pasj/psz050 　

ISSN： 2053-051X

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<jats:title>Abstract</jats:title> <jats:p>We present an overview of a deep transient survey of the COSMOS field with the Subaru Hyper Suprime-Cam (HSC). The survey was performed for the 1.77 deg2 ultra-deep layer and 5.78 deg2 deep layer in the Subaru Strategic Program over six- and four-month periods from 2016 to 2017, respectively. The ultra-deep layer reaches a median depth per epoch of 26.4, 26.3, 26.0, 25.6, and 24.6 mag in g, r, i, z, and y bands, respectively; the deep layer is ∼0.6 mag shallower. In total, 1824 supernova candidates were identified. Based on light-curve fitting and derived light-curve shape parameter, we classified 433 objects as Type Ia supernovae (SNe); among these candidates, 129 objects have spectroscopic or COSMOS2015 photometric redshifts and 58 objects are located at z > 1. Our unique data set doubles the number of Type Ia SNe at z > 1 and enables various time-domain analyses of Type II SNe, high-redshift superluminous SNe, variable stars, and active galactic nuclei.</jats:p>
Searches for Population III pair-instability supernovae: Predictions for ULTIMATE-Subaru and WFIRST Peer-reviewed

Moriya Takashi J, Wong Kenneth C, Koyama Yusei, Tanaka Masaomi, Oguri Masamune, Hilbert Stefan, Nomoto Ken'ichi

PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN　71　(3)　2019/06

DOI： 10.1093/pasj/psz035 　

ISSN： 0004-6264

eISSN： 2053-051X
The nature of PISN candidates: clues from nebular spectra

P A Mazzali, T J Moriya, M Tanaka, S E Woosley

Monthly Notices of the Royal Astronomical Society　484　(3)　3451-3462　2019/04/11
Publisher: Oxford University Press (OUP)
DOI： 10.1093/mnras/stz177 　

ISSN： 0035-8711

eISSN： 1365-2966
SN 2017czd: A Rapidly Evolving Supernova from a Weak Explosion of a Type IIb Supernova Progenitor Peer-reviewed

Nakaoka Tatsuya, Moriya Takashi J, Tanaka Masaomi, Yamanaka Masayuki, Kawabata Koji S, Maeda Keiichi, Kawabata Miho, Kawahara Naoki, Itagaki Koichi, Ouchi Ryoma, Blinnikov Sergei I, Tominaga Nozomu, Uemura Makoto

ASTROPHYSICAL JOURNAL　875　(1)　76-76　2019/04/10

DOI： 10.3847/1538-4357/ab0dfe 　

ISSN： 0004-637X

eISSN： 1538-4357
First Release of High-Redshift Superluminous Supernovae from the Subaru HIgh-Z SUpernova CAmpaign (SHIZUCA). I. Photometric Properties Peer-reviewed

Moriya Takashi J, Tanaka Masaomi, Yasuda Naoki, Jiang Ji-an, Lee Chien-Hsiu, Maeda Keiichi, Morokuma Tomoki, Nomoto Keni'chi, Quimby Robert M, Suzuki Nao, Takahashi Ichiro, Tanaka Masayuki, Tominaga Nozomu, Yamaguchi Masaki, Bernard, Stephanie R, Cooke Jeff, Curtin Chris, Galbany Lluis, Gonzalez-Gaitan Santiago, Pignata Giuliano, Pritchard Tyler, Komiyama Yutaka, Lupton Robert H

ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES　241　(2)　16-16　2019/04

DOI： 10.3847/1538-4365/ab07c5 　

ISSN： 0067-0049

eISSN： 1538-4365
First Release of High-redshift Superluminous Supernovae from the Subaru HIgh-Z SUpernova CAmpaign (SHIZUCA). II. Spectroscopic Properties Peer-reviewed

Curtin Chris, Cooke Jeff, Moriya Takashi J, Tanaka Masayuki, Quimby Robert M, Bernard, Stephanie R, Galbany Lluis, Jiang Ji-an, Lee Chien-Hsiu, Maeda Keiichi, Morokuma Tomoki, Nomoto Ken'ichi, Pignata Giuliano, Pritchard Tyler, Suzuki Nao, Takahashi Ichiro, Tanaka Masaomi, Tominaga Nozomu, Yamaguchi Masaki, Yasuda Naoki

ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES　241　(2)　17-17　2019/04

DOI： 10.3847/1538-4365/ab07c8 　

ISSN： 0067-0049

eISSN： 1538-4365
Synthetic spectra of energetic core-collapse supernovae and the early spectra of SN 2007bi and SN 1999as Peer-reviewed

Moriya Takashi J, Mazzali Paolo A, Tanaka Masaomi

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY　484　(3)　3443-3450　2019/04

DOI： 10.1093/mnras/stz262 　

ISSN： 0035-8711

eISSN： 1365-2966
The fast, luminous ultraviolet transient AT2018cow: extreme supernova, or disruption of a star by an intermediate-mass black hole? Peer-reviewed

Perley Daniel A, Mazzali Paolo A, Yan Lin, Cenko S. Bradley, Gezari Suvi, Taggart Kirsty, Blagorodnova Nadia, Fremling Christoffer, Mockler Brenna, Singh Avinash, Tominaga Nozomu, Tanaka Masaomi, Watson Alan M, Ahumada Tomas, Anupama G. C, Ashall Chris, Becerra Rosa L, Bersier David, Bhalerao Varun, Bloom Joshua S, Butler Nathaniel R, Copperwheat Chris, Coughlin Michael W, De Kishalay, Drake Andrew J, Duev Dmitry A, Frederick Sara, Jesus Gonzalez J, Goobar Ariel, Heida Marianne, Ho Anna Y. Q, Horst John, Hung Tiara, Itoh Ryosuke, Jencson Jacob E, Kasliwal Mansi M, Kawai Nobuyuki, Khanam Tanazza, Kulkarni Shrinivas R, Kumar Brajesh, Kumar Harsh, Kutyrev Alexander S, Lee William H, Maeda Keiichi, Mahabal Ashish, Murata Katsuhiro L, Neill James D, Ngeow Chow-Choong, Penprase Bryan, Pian Elena, Quimby Robert, Ramirez-Ruiz Enrico, Richer Michael G, Roman-Zuniga Carlos G, Sahu D. K, Srivastav Shubham, Socia Quentin, Sollerman Jesper, Tachibana Yutaro, Taddia Francesco, Tinyanont Samaporn, Troja Eleonora, Ward Charlotte, Wee Jerrick, Yu Po-Chieh

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY　484　(1)　1031-1049　2019/03

DOI： 10.1093/mnras/sty3420 　

ISSN： 0035-8711

eISSN： 1365-2966
A Long-duration Luminous Type IIn Supernova KISS15s: Strong Recombination Lines from the Inhomogeneous Ejecta-CSM Interaction Region and Hot Dust Emission from Newly Formed Dust Peer-reviewed

Kokubo Mitsuru, Mitsuda Kazuma, Morokuma Tomoki, Tominaga Nozomu, Tanaka Masaomi, Moriya Takashi J, Yoachim Peter, Ivezic Zeljko, Sako Shigeyuki, Doi Mamoru

ASTROPHYSICAL JOURNAL　872　(2)　2019/02/20

DOI： 10.3847/1538-4357/aaff6b 　

ISSN： 0004-637X
Extended Calculations of Energy Levels and Transition Rates of Nd II-IV Ions for Application to Neutron Star Mergers Peer-reviewed

Gaigalas Gediminas, Kato Daiji, Rynkun Pavel, Radziute Laima, Tanaka Masaomi

ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES　240　(2)　2019/02

DOI： 10.3847/1538-4365/aaf9b8 　

ISSN： 0067-0049
Subaru High-z Exploration of Low-luminosity Quasars (SHELLQs). X. Discovery of 35 Quasars and Luminous Galaxies at 5.7 ≤ z ≤ 7.0 Peer-reviewed

Matsuoka, Y., Iwasawa, K., Onoue, M., Kashikawa, N., Strauss, M.A., Lee, C.-H., Imanishi, M., Nagao, T., Akiyama, M., Asami, N., Bosch, J., Furusawa, H., Goto, T., Gunn, J.E., Harikane, Y., Ikeda, H., Izumi, T., Kawaguchi, T., Kato, N., Kikuta, S., Kohno, K., Komiyama, Y., Koyama, S., Lupton, R.H., Minezaki, T., Miyazaki, S., Murayama, H., Niida, M., Nishizawa, A.J., Noboriguchi, A., Oguri, M., Ono, Y., Ouchi, M., Price, P.A., Sameshima, H., Schulze, A., Silverman, J.D., Sugiyama, N., Tait, P.J., Takada, M., Takata, T., Tanaka, M., Tang, J.-J., Toba, Y., Utsumi, Y., Wang, S.-Y., Yamashita, T.

Astrophysical Journal　883　(2)　183-183　2019
Publisher: American Astronomical Society
DOI： 10.3847/1538-4357/ab3c60 　

ISSN： 0004-637X

eISSN： 1538-4357
The Hyper Suprime-Cam SSP transient survey in COSMOS: Overview Peer-reviewed

Yasuda, N., Tanaka, M., Tominaga, N., Jiang, J.-A., Moriya, T.J., Morokuma, T., Suzuki, N., Takahashi, I., Yamaguchi, M.S., Maeda, K., Sako, M., Ikeda, S., Kimura, A., Morii, M., Ueda, N., Yoshida, N., Lee, C.-H., Suyu, S.H., Komiyama, Y., Regnault, N., Rubin, D.

Publications of the Astronomical Society of Japan　71　(4)　2019

DOI： 10.1093/pasj/psz050 　

ISSN： 0004-6264
The origin of polarization in kilonovae and the case of the gravitational-wave counterpart AT 2017gfo Peer-reviewed

Mattia Bulla, Stefano Covino, Koutarou Kyutoku, Masaomi Tanaka, Justyn R. Maund, Ferdinando Patat, Kenji Toma, Klaas Wiersema, James Bruten, Zi-Ping Jin, Vincenzo Testa

Nature Astronomy　2018/11

DOI： 10.1038/s41550-018-0593-y 　
Radiative Transfer Simulation for the Optical and Near-infrared Electromagnetic Counterparts to GW170817 Peer-reviewed

Kawaguchi Kyohei, Shibata Masaru, Tanaka Masaomi

ASTROPHYSICAL JOURNAL LETTERS　865　(2)　2018/10/01

DOI： 10.3847/2041-8213/aade02 　

ISSN： 2041-8205
The University of Tokyo Atacama Observatory 6.5m telescope: project overview and current status

Doi, M, Miyata, T, Yoshii, Y, Kohno, K, Tanaka, M, Motohara, K, Minezaki, T, Kawara, K, Sako, S, Morokuma, T, Tamura, Y, Tanabe, T, Hatsukade, B, Takahashi, H, Konishi, M, Kamizuka, T, Kato, N, Aoki, T, Soyano, T, Tarusawa, K, Handa, T, Koshida, S, Bronfman, L, Ruiz, M. T, Hamuy, M, Mendez, R, Garay, G, Escala, A

Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series　10700　107000W　2018/07

DOI： 10.1117/12.2313099 　
Multi-band Polarization of Type IIP Supernovae Due to Light Echo from Circumstellar Dust Peer-reviewed

Nagao Takashi, Maeda Keiichi, Tanaka Masaomi

ASTROPHYSICAL JOURNAL　861　(1)　2018/07/01

DOI： 10.3847/1538-4357/aac94e 　

ISSN： 0004-637X
Free Neutron Ejection from Shock Breakout in Binary Neutron Star Mergers Peer-reviewed

Ishii Ayako, Shigeyama Toshikazu, Tanaka Masaomi

ASTROPHYSICAL JOURNAL　861　(1)　25-25　2018/07/01

DOI： 10.3847/1538-4357/aac385 　

ISSN： 0004-637X

eISSN： 1538-4357
Multi-band Polarization of Type IIP Supernovae Due to Light Echo from Circumstellar Dust Peer-reviewed

Nagao, Takashi, Maeda, Keiichi, Tanaka, Masaomi

The Astrophysical Journal　861　1　2018/06

DOI： 10.3847/1538-4357/aac94e 　

ISSN： 1538-4357
Transient survey rates for orphan afterglows from compact merger jets Peer-reviewed

Gavin P. Lam, Masaomi Tanaka, Shiho Kobayashi

Monthly Notices of the Royal Astronomical Society　476　(4)　4435-4441　2018/06/01

DOI： 10.1093/mnras/sty484 　

ISSN： 1365-2966 0035-8711
The Low-luminosity Type IIP Supernova 2016bkv with Early-phase Circumstellar Interaction Peer-reviewed

Tatsuya Nakaoka, Koji S. Kawabata, Keiichi Maeda, Masaomi Tanaka, Masayuki Yamanaka, Takashi J. Moriya, Nozomu Tominaga, Tomoki Morokuma, Katsutoshi Takaki, Miho Kawabata, Naoki Kawahara, Ryosuke Itoh, Kensei Shiki, Hiroki Mori, Jun Hirochi, Taisei Abe, Makoto Uemura, Michitoshi Yoshida, Hiroshi Akitaya, Yuki Moritani, Issei Ueno, Takeshi Urano, Mizuki Isogai, Hidekazu Hanayama, Takahiro Nagayama

Astrophysical Journal　859　(2)　2018/06/01

DOI： 10.3847/1538-4357/aabee7 　

ISSN： 1538-4357 0004-637X
Broad-line Type Ic supernova SN 2014ad Peer-reviewed

D. K. Sahu, G. C. Anupama, N. K. Chakradhari, S. Srivastav, Masaomi Tanaka, Keiichi Maeda, Ken'ichi Nomoto

Monthly Notices of the Royal Astronomical Society　475　(2)　2591-2604　2018/04/01

DOI： 10.1093/mnras/stx3212 　

ISSN： 1365-2966 0035-8711
Intermediate-mass Elements in Young Supernova Remnants Reveal Neutron Star Kicks by Asymmetric Explosions Peer-reviewed

Satoru Katsuda, Mikio Morii, Hans-Thomas Janka, Annop Wongwathanarat, Ko Nakamura, Kei Kotake, Koji Mori, Ewald Müller, Tomoya Takiwaki, Masaomi Tanaka, Nozomu Tominaga, Hiroshi Tsunemi

Astrophysical Journal　856　(1)　2018/03/20

DOI： 10.3847/1538-4357/aab092 　

ISSN： 1538-4357 0004-637X
Subaru Hyper Suprime-Cam Survey for an optical counterpart of GW170817 Peer-reviewed

Nozomu Tominaga, Masaomi Tanaka, Tomoki Morokuma, Yousuke Utsumi, Masaki S Yamaguchi, Naoki Yasuda, Masayuki Tanaka, Michitoshi Yoshida, Takuya Fujiyoshi, Hisanori Furusawa, Koji S Kawabata, Chien-Hsiu Lee, Kentaro Motohara, Ryou Ohsawa, Kouji Ohta, Tsuyoshi Terai, Fumio Abe, Wako Aoki, Yuichiro Asakura, Sudhanshu Barway, Ian A Bond, Kenta Fujisawa, Satoshi Honda, Kunihito Ioka, Youichi Itoh, Nobuyuki Kawai, Ji Hoon Kim, Naoki Koshimoto, Kazuya Matsubayashi, Shota Miyazaki, Tomoki Saito, Yuichiro Sekiguchi, Takahiro Sumi, Paul J Tristram, J-Gem Collaboration

Publications of the Astronomical Society of Japan　70　(2)　1-11　2018/03/01

DOI： 10.1093/pasj/psy007 　

ISSN： 2053-051X 0004-6264
A surge of light at the birth of a supernova Peer-reviewed

Bersten, M. C, Folatelli, G, García, F, van Dyk, S. D, Benvenuto, O. G, Orellana, M, Buso, V, Sánchez, J. L, Tanaka, M, Maeda, K, Filippenko, A. V, Zheng, W, Brink, T. G, Cenko, S. B, de Jaeger, T, Kumar, S, Moriya, T. J, Nomoto, K, Perley, D. A, Shivvers, I, Smith, N

Nature　554　497　2018/02

DOI： 10.1038/nature25151 　
X-Ray Light Curve and Spectra of Shock Breakout in a Wind Peer-reviewed

Yukari Ohtani, Akihiro Suzuki, Toshikazu Shigeyama, Masaomi Tanaka

Astrophysical Journal　853　(1)　2018/01/20

DOI： 10.3847/1538-4357/aaa482 　

ISSN： 1538-4357 0004-637X
Properties of Kilonovae from Dynamical and Post-merger Ejecta of Neutron Star Mergers Peer-reviewed

Masaomi Tanaka, Daiji Kato, Gediminas Gaigalas, Pavel Rynkun, Laima Radžiute, Shinya Wanajo, Yuichiro Sekiguchi, Nobuyuki Nakamura, Hajime Tanuma, Izumi Murakami, Hiroyuki A. Sakaue

Astrophysical Journal　852　(2)　2018/01/10

DOI： 10.3847/1538-4357/aaa0cb 　

ISSN： 1538-4357 0004-637X
Identifying subclasses of young type Ia supernova remnants by X-ray observations

Satoru Katsuda, Koji Mori, Keiichi Maeda, Masaomi Tanaka, Katsuji Koyama, Hiroshi Tsunemi, Hiroshi Nakajima, Yoshitomo Maeda, Masanobu Ozaki, Robert Petre

14th Marcel Grossman Meeting On Recent Developments in Theoretical and Experimental General Relativity, Astrophysics and Relativistic Field Theories, Proceedings　1915-1921　2018
Publisher: World Scientific Publishing Co. Pte. Ltd.
DOI： 10.1142/9789813226609_0203 　
Classification of Variable Stars with Incomplete Data

Record of Joint Conference of Electrical and Electronics Engineers in Kyushu　2018　272-272　2018
Publisher: Committee of Joint Conference of Electrical, Electronics and Information Engineers in Kyushu
DOI： 10.11527/jceeek.2018.0_272 　
The radio structure of the peculiar narrow-line Seyfert 1 galaxy candidate J1100+4421 Peer-reviewed

K. Gabányi, S. Frey, Z. Paragi, E. Järvelä, T. Morokuma, T. An, M. Tanaka, I. Tar

Monthly Notices of the Royal Astronomical Society　473　(2)　1554-1561　2018/01/01
Publisher: Oxford University Press
DOI： 10.1093/mnras/stx2449 　

ISSN： 1365-2966 0035-8711
The Hyper Suprime-Cam SSP survey: Overview and survey design Peer-reviewed

Hiroaki Aihara, Nobuo Arimoto, Robert Armstrong, Stéphane Arnouts, Neta A. Bahcall, Steven Bickerton, James Bosch, Kevin Bundy, Peter L. Capak, James H. H. Chan, Masashi Chiba, Jean Coupon, Eiichi Egami, Motohiro Enoki, Francois Finet, Hiroki Fujimori, Seiji Fujimoto, Hisanori Furusawa, Junko Furusawa, Tomotsugu Goto, Andy Goulding, Johnny P. Greco, Jenny E. Greene, James E. Gunn, Takashi Hamana, Yuichi Harikane, Yasuhiro Hashimoto, Takashi Hattori, Masao Hayashi, Yusuke Hayashi, Krzysztof G. Hełminiak, Ryo Higuchi, Chiaki Hikage, Paul T. P. Ho, Bau-Ching Hsieh, Kuiyun Huang, Song Huang, Hiroyuki Ikeda, Masatoshi Imanishi, Akio K. Inoue, Kazushi Iwasawa, Ikuru Iwata, Anton T. Jaelani, Hung-Yu Jian, Yukiko Kamata, Hiroshi Karoji, Nobunari Kashikawa, Nobuhiko Katayama, Satoshi Kawanomoto, Issha Kayo, Jin Koda, Michitaro Koike, Takashi Kojima, Yutaka Komiyama, Akira Konno, Shintaro Koshida, Yusei Koyama, Haruka Kusakabe, Alexie Leauthaud, Chien-Hsiu Lee, Lihwai Lin, Yen-Ting Lin, Robert H. Lupton, Rachel Mandelbaum, Yoshiki Matsuoka, Elinor Medezinski, Sogo Mineo, Shoken Miyama, Hironao Miyatake, Satoshi Miyazaki, Rieko Momose, Anupreeta More, Surhud More, Yuki Moritani, Takashi J. M. Oriya, Tomoki Morokuma, Shiro Mukae, Ryoma Murata, Hitoshi Murayama, Tohru Nagao, Fumiaki Nakata, Mana Niida, Hiroko Niikura, Atsushi J. Nishizawa, Yoshiyuki Obuchi, Masamune Oguri, Yukie Oishi, Nobuhiro Okabe, Sakurako Okamoto, Yuki Okura, Yoshiaki Ono, Masato Onodera, Masafusa Onoue, Ken Osato, Masami Ouchi, Paul A. Price, Tae-Soo Pyo, Masao Sako, Marcin Sawicki, Takatoshi Shibuya, Kazuhiro Shimasaku, Atsushi Shimono, Masato Shirasaki, John D. Silverman, Melanie Simet, Joshua Speagle, David N. Spergel, Michael A. Strauss, Yuma Sugahara, Naoshi Sugiyama, Yasushi Suto, Sherry H. Suyu, Nao Suzuki, Philip J. Tait, Masahiro Takada, Tadafumi Takata, Naoyuki Tamura, Manobu M. Tanaka, Masaomi Tanaka, Masayuki Tanaka, Yoko Tanaka, Tsuyoshi Terai, Yuichi Terashima, Yoshiki Toba, Nozomu Tominaga, Jun Toshikawa, Edwin L. Turner, Tomohisa Uchida, Hisakazu Uchiyama, Keiichi Umetsu, Fumihiro Uraguchi, Yu Ji Urata, Tomonori Usuda, Yousuke Utsumi, Shiang-Yu Wang, Wei-Hao Wang, Kenneth C. Wong, Kiyoto Yabe, Yoshihiko Yamada, Hitomi Yamanoi, Naoki Yasuda, Sherry Yeh, Atsunori Yonehara, Suraphong Yuma

Publications of the Astronomical Society of Japan　70　(1)　2018/01/01

DOI： 10.1093/pasj/psx066 　

ISSN： 2053-051X 0004-6264

eISSN： 2053-051X
A challenge to identify an optical counterpart of the gravitational wave event GW151226 with Hyper Suprime-Cam Peer-reviewed

Yousuke Utsumi, Nozomu Tominaga, Masaomi Tanaka, Tomoki Morokuma, Michitoshi Yoshida, Yuichiro Asakura, François Finet, Hisanori Furusawa, Koji S. Kawabata, Wei Liu, Kazuya Matsubayashi, Yuki Moritani, Kentaro Motohara, Fumiaki Nakata, Kouji Ohta, Tsuyoshi Terai, Makoto Uemura, Naoki Yasuda, on behalf of the J-GEM collaboration

Publications of the Astronomical Society of Japan　70　(1)　11-114　2018/01/01

DOI： 10.1093/pasj/psx125 　

ISSN： 2053-051X 0004-6264
Conceptual design of a wide-field near UV transient survey in a 6U CubeSat Peer-reviewed

Yatsu Yoichi, Ozawa Toshiki, Sasaki Kenichi, Mamiya Hideo, Kawai Nobuyuki, Kikuya Yuhei, Matsushita Masanori, Matunaga Saburo, Nikzad Shouleh, Bilgi Pavan, Kulkarni Shrinivas R, Tominaga Nozomu, Tanaka Masaomi, Morokuma Tomoki, Takeyama Norihide, Enokuchi Akito

SPACE TELESCOPES AND INSTRUMENTATION 2018: ULTRAVIOLET TO GAMMA RAY　10699　2018

DOI： 10.1117/12.2313026 　

ISSN： 0277-786X

eISSN： 1996-756X
The Tomo-e Gozen wide field CMOS camera for the Kiso Schmidt telescope Peer-reviewed

Shigeyuki Sako, Ryou Ohsawa, Hidenori Takahashi, Yuto Kojima, Mamoru Doi, Naoto Kobayashi, Tsutomu Aoki, Noriaki Arima, Ko Arimatsu, Makoto Ichiki, Shiro Ikeda, Kota Inooka, Yoshifusa Ita, Toshihiro Kasuga, Mitsuru Kokubo, Masahiro Konishi, Hiroyuki Maehara, Noriyuki Matsunaga, Kazuma Mitsuda, Takashi Miyata, Yuki Mori, Mikio Morii, Tomoki Morokuma, Kentaro Motohara, Yoshikazu Nakada, Shin Ichiro Okumura, Yuki Sarugaku, Mikiya Sato, Toshikazu Shigeyama, Takao Soyano, Masaomi Tanaka, Ken'Ichi Tarusawa, Nozomu Tominaga, Tomonori Totani, Seitaro Urakawa, Fumihiko Usui, Junichi Watanabe, Takuya Yamashita, Makoto Yoshikawa

Proceedings of SPIE - The International Society for Optical Engineering　10702　2018

DOI： 10.1117/12.2310049 　

ISSN： 0277-786X

eISSN： 1996-756X
Evaluation of large pixel CMOS image sensors for the Tomo-e Gozen wide field camera Peer-reviewed

Yuto Kojima, Shigeyuki Sako, Ryou Ohsawa, Hidenori Takahashi, Mamoru Doi, Naoto Kobayashi, Tsutomu Aoki, Noriaki Arima, Ko Arimatsu, Makoto Ichiki, Shiro Ikeda, Kota Inooka, Yoshifusa Ita, Toshihiro Kasuga, Mitsuru Kokubo, Masahiro Konishi, Hiroyuki Maehara, Noriyuki Matsunaga, Kazuma Mitsuda, Takashi Miyata, Yuki Mori, Mikio Morii, Tomoki Morokuma, Kentaro Motohara, Yoshikazu Nakada, Shin Ichiro Okumura, Yuki Sarugaku, Mikiya Sato, Toshikazu Shigeyama, Takao Soyano, Masaomi Tanaka, Ken'ichi Tarusawa, Nozomu Tominaga, Tomonori Totani, Seitaro Urakawa, Fumihiko Usui, Junichi Watanabe, Takuya Yamashita, Makoto Yoshikawa

Proceedings of SPIE - The International Society for Optical Engineering　10709　2018

DOI： 10.1117/12.2311301 　

ISSN： 0277-786X

eISSN： 1996-756X
SN 2016jhj at redshift 0.34: extending the Type II supernova Hubble diagram using the standard candle method Peer-reviewed

T. de Jaeger, L. Galbany, A. V. Filippenko, S. Gonzalez-Gaitan, N. Yasuda, K. Maeda, M. Tanaka, T. Morokuma, T. J. Moriya, N. Tominaga, K. Nomoto, Y. Komiyama, J. P. Anderson, T. G. Brink, R. G. Carlberg, G. Folatelli, M. Hamuy, G. Pignata, W. Zheng

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY　472　(4)　4233-4243　2017/12

DOI： 10.1093/mnras/stx2300 　

ISSN： 0035-8711

eISSN： 1365-2966
J-GEM observations of an electromagnetic counterpart to the neutron star merger GW170817 Peer-reviewed

Utsumi, Yousuke, Tanaka, Masaomi, Tominaga, Nozomu, Yoshida, Michitoshi, Barway, Sudhanshu, Nagayama, Takahiro, Zenko, Tetsuya, Aoki, Kentaro, Fujiyoshi, Takuya, Furusawa, Hisanori, Kawabata, Koji S, Koshida, Shintaro, Lee, Chien-Hsiu, Morokuma, Tomoki, Motohara, Kentaro, Nakata, Fumiaki, Ohsawa, Ryou, Ohta, Kouji, Okita, Hirofumi, Tajitsu, Akito, Tanaka, Ichi, Terai, Tsuyoshi, Yasuda, Naoki, Abe, Fumio, Asakura, Yuichiro, Bond, Ian A, Miyazaki, Shota, Sumi, Takahiro, Tristram, Paul J, Honda, Satoshi, Itoh, Ryosuke, Itoh, Yoichi, Kawabata, Miho, Morihana, Kumiko, Nagashima, Hiroki, Nakaoka, Tatsuya, Ohshima, Tomohito, Takahashi, Jun, Takayama, Masaki, Aoki, Wako, Baar, Stefan, Doi, Mamoru, Finet, Francois, Kanda, Nobuyuki, Kawai, Nobuyuki, Kim, Ji Hoon, Kuroda, Daisuke, Liu, Wei, Matsubayashi, Kazuya, Murata, Katsuhiro L, Nagai, Hiroshi, Saito, Tomoki, Saito, Yoshihiko, Sako, Shigeyuki, Sekiguchi, Yuichiro, Tamura, Yoichi, Tanaka, Masayuki, Uemura, Makoto, Yamaguchi, Masaki S

Publications of the Astronomical Society of Japan　69　101　2017/12/01

DOI： 10.1093/pasj/psx118 　

ISSN： 2053-051X
Modeling GW170817 based on numerical relativity and its implications Peer-reviewed

Masaru Shibata, Sho Fujibayashi, Kenta Hotokezaka, Kenta Kiuchi, Koutarou Kyutoku, Yuichiro Sekiguchi, Masaomi Tanaka

PHYSICAL REVIEW D　96　(12)　2017/12

DOI： 10.1103/PhysRevD.96.123012 　

ISSN： 2470-0010

eISSN： 2470-0029
Kilonova from post-merger ejecta as an optical and near-infrared counterpart of GW170817 Peer-reviewed

Masaomi Tanaka, Yousuke Utsumi, Paolo A. Mazzali, Nozomu Tominaga, Michitoshi Yoshida, Yuichiro Sekiguchi, Tomoki Morokuma, Kentaro Motohara, Kouji Ohta, Koji S. Kawabata, Fumio Abe, Kentaro Aoki, Yuichiro Asakura, Stefan Baar, Sudhanshu Barway, Ian A. Bond, Mamoru Doi, Takuya Fujiyoshi, Hisanori Furusawa, Satoshi Honda, Yoichi Itoh, Miho Kawabata, Nobuyuki Kawai, Ji Hoon Kim, Chien-Hsiu Lee, Shota Miyazaki, Kumiko Morihana, Hiroki Nagashima, Takahiro Nagayama, Tatsuya Nakaoka, Fumiaki Nakata, Ryou Ohsawa, Tomohito Ohshima, Hirofumi Okita, Tomoki Saito, Takahiro Sumi, Akito Tajitsu, Jun Takahashi, Masaki Takayama, Yoichi Tamura, Ichi Tanaka, Tsuyoshi Terai, Paul J. Tristram, Naoki Yasuda, Tetsuya Zenko

PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN　69　(6)　2017/10/16

DOI： 10.1093/pasj/psx121 　

ISSN： 0004-6264
J-GEM observations of an electromagnetic counterpart to the neutron star merger GW170817 Peer-reviewed

Yousuke Utsumi, Masaomi Tanaka, Nozomu Tominaga, Michitoshi Yoshida, Sudhanshu Barway, Takahiro Nagayama, Tetsuya Zenko, Kentaro Aoki, Takuya Fujiyoshi, Hisanori Furusawa, Koji S. Kawabata, Shintaro Koshida, Chien-Hsiu Lee, Tomoki Morokuma, Kentaro Motohara, Fumiaki Nakata, Ryou Ohsawa, Kouji Ohta, Hirofumi Okita, Akito Tajitsu, Ichi Tanaka, Tsuyoshi Terai, Naoki Yasuda, Fumio Abe, Yuichiro Asakura, Ian A. Bond, Shota Miyazaki, Takahiro Sumi, Paul J. Tristram, Satoshi Honda, Ryosuke Itoh, Yoichi Itoh, Miho Kawabata, Kumiko Morihana, Hiroki Nagashima, Tatsuya Nakaoka, Tomohito Ohshima, Jun Takahashi, Masaki Takayama, Wako Aoki, Stefan Baar, Mamoru Doi, François Finet, Nobuyuki Kanda, Nobuyuki Kawai, Ji Hoon Kim, Daisuke Kuroda, Wei Liu, Kazuya Matsubayashi, Katsuhiro L. Murata, Hiroshi Nagai, Tomoki Saito, Yoshihiko Saito, Shigeyuki Sako, Yuichiro Sekiguchi, Yoichi Tamura, Masayuki Tanaka, Makoto Uemura, Masaki S. Yamaguchi, the J-GEM collaboration

PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN　69　(6)　2017/10/16

DOI： 10.1093/pasj/psx118 　

ISSN： 0004-6264
A hybrid type Ia supernova with an early flash triggered by helium-shell detonation Peer-reviewed

Ji-an Jiang, Mamoru Doi, Keiichi Maeda, Toshikazu Shigeyama, Ken'ichi Nomoto, Naoki Yasuda, Saurabh W. Jha, Masaomi Tanaka, Tomoki Morokuma, Nozomu Tominaga, Zeljko Ivezic, Pilar Ruiz-Lapuente, Maximilian D. Stritzinger, Paolo A. Mazzali, Christopher Ashall, Jeremy Mould, Dietrich Baade, Nao Suzuki, Andrew J. Connolly, Ferdinando Patat, Lifan Wang, Peter Yoachim, David Jones, Hisanori Furusawa, Satoshi Miyazaki

NATURE　550　(7674)　80-+　2017/10

DOI： 10.1038/nature23908 　

ISSN： 0028-0836

eISSN： 1476-4687
Spectropolarimetry of stripped-envelope supernovae: observations and modelling Peer-reviewed

Masaomi Tanaka

PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES　375　(2105)　2017/10

DOI： 10.1098/rsta.2016.0273 　

ISSN： 1364-503X

eISSN： 1471-2962
OISTER optical and near-infrared monitoring observations of peculiar radio-loud active galactic nucleus SDSSJ110006.07+442144.3 Peer-reviewed

Tomoki Morokuma, Masaomi Tanaka, Yasuyuki T. Tanaka, Ryosuke Itoh, Nozomu Tominaga, Poshak Gandhi, Elena Pian, Paolo Mazzali, Kouji Ohta, Emiko Matsumoto, Takumi Shibata, Hinako Akimoto, Hiroshi Akitaya, Gamal B. Ali, Tsutomu Aoki, Mamoru Doi, Nana Ebisuda, Ahmed Essam, Kenta Fujisawa, Hideo Fukushima, Shuhei Goda, Yuya Gouda, Hidekazu Hanayama, Yasuhito Hashiba, Osamu Hashimoto, Kenzo Hayashida, Yuichiro Hiratsuka, Satoshi Honda, Masataka Imai, Kanichiro Inoue, Michiko Ishibashi, Ikuru Iwata, Hideyuki Izumiura, Yuka Kanda, Miho Kawabata, Kenji Kawaguchi, Nobuyuki Kawai, Mitsuru Kokubo, Daisuke Kuroda, Hiroyuki Maehara, Hiroyuki Mito, Kazuma Mitsuda, Ryota Miyagawa, Takeshi Miyaji, Yusuke Miyamoto, Kumiko Morihana, Yuki Moritani, Kana Morokuma-Matsui, Kotone Murakami, Katsuhiro L. Murata, Takahiro Nagayama, Kazuki Nakamura, Tatsuya Nakaoka, Kotaro Niinuma, Takafumi Nishimori, Daisaku Nogami, Yumiko Oasa, Tatsunori Oda, Tomohito Ohshima, Yoshihiko Saito, Shuichiro Sakata, Shigeyuki Sako, Yuki Sarugaku, Satoko Sawada-Satoh, Genta Seino, Kazuo Sorai, Takao Soyano, Francesco Taddia, Jun Takahashi, Yuhei Takagi, Katsutoshi Takaki, Koji Takata, Ken'ichi Tarusawa, Makoto Uemura, Takahiro Ui, Riku Urago, Kazutoshi Ushioda, Jun-ichi Watanabe, Makoto Watanabe, Satoshi Yamashita, Kenshi Yanagisawa, Yoshinori Yonekura, Michitoshi Yoshida

PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN　69　(5)　2017/10

DOI： 10.1093/pasj/psx075 　

ISSN： 0004-6264

eISSN： 2053-051X
Circumstellar Light Echo as a Possible Origin of the Polarization of Type IIP Supernovae Peer-reviewed

Takashi Nagao, Keiichi Maeda, Masaomi Tanaka

ASTROPHYSICAL JOURNAL　847　(2)　2017/10

DOI： 10.3847/1538-4357/aa8b0d 　

ISSN： 0004-637X

eISSN： 1538-4357
Single-Epoch Supernova Classification with Deep Convolutional Neural Networks Peer-reviewed

Akisato Kimura, Ichiro Takahashi, Masaomi Tanaka, Naoki Yasuda, Naonori Ueda, Naoki Yoshida

Proceedings - IEEE 37th International Conference on Distributed Computing Systems Workshops, ICDCSW 2017　354-359　2017/07/13

DOI： 10.1109/ICDCSW.2017.47 　

ISSN： 1545-0678
Superluminous Transients at AGN Centers from Interaction between Black Hole Disk Winds and Broad-line Region Clouds Peer-reviewed

Takashi J. Moriya, Masaomi Tanaka, Tomoki Morokuma, Ken Ohsuga

ASTROPHYSICAL JOURNAL LETTERS　843　(2)　2017/07

DOI： 10.3847/2041-8213/aa7af3 　

ISSN： 2041-8205

eISSN： 2041-8213
A new, faint population of X-ray transients Peer-reviewed

Franz E. Bauer, Ezequiel Treister, Kevin Schawinski, Steve Schulze, Bin Luo, David M. Alexander, William N. Brandt, Andrea Comastri, Francisco Forster, Roberto Gilli, David Alexander Kann, Keiichi Maeda, Ken'ichi Nomoto, Maurizio Paolillo, Piero Ranalli, Donald P. Schneider, Ohad Shemmer, Masaomi Tanaka, Alexey Tolstov, Nozomu Tominaga, Paolo Tozzi, Cristian Vignali, Junxian Wang, Yongquan Xue, Guang Yang

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY　467　(4)　4841-4857　2017/06

DOI： 10.1093/mnras/stx417 　

ISSN： 0035-8711

eISSN： 1365-2966
Light-curve and spectral properties of ultrastripped core-collapse supernovae leading to binary neutron stars Peer-reviewed

Takashi J. Moriya, Paolo A. Mazzali, Nozomu Tominaga, Stephan Hachinger, Sergei I. Blinnikov, Thomas M. Tauris, Koh Takahashi, Masaomi Tanaka, Norbert Langer, Philipp Podsiadlowski

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY　466　(2)　2085-2098　2017/04

DOI： 10.1093/mnras/stw3225 　

ISSN： 0035-8711

eISSN： 1365-2966
Broad-lined Supernova 2016coi with a Helium Envelope Peer-reviewed

Masayuki Yamanaka, Tatsuya Nakaoka, Masaomi Tanaka, Keiichi Maeda, Satoshi Honda, Hidekazu Hanayama, Tomoki Morokuma, Masataka Imai, Kenzo Kinugasa, Katsuhiro L. Murata, Takefumi Nishimori, Osamu Hashimoto, Hirotaka Gima, Kensuke Hosoya, Ayano Ito, Mayu Karita, Miho Kawabata, Kumiko Morihana, Yuto Morikawa, Kotone Murakami, Takahiro Nagayama, Tatsuharu Ono, Hiroki Onozato, Yuki Sarugaku, Mitsuteru Sato, Daisuke Suzuki, Jun Takahashi, Masaki Takayama, Hijiri Yaguchi, Hiroshi Akitaya, Yuichiro Asakura, Koji S. Kawabata, Daisuke Kuroda, Daisaku Nogami, Yumiko Oasa, Toshihiro Omodaka, Yoshihiko Saito, Kazuhiro Sekiguchi, Nozomu Tominaga, Makoto Uemura, Makoto Watanabe

ASTROPHYSICAL JOURNAL　837　(1)　2017/03

DOI： 10.3847/1538-4357/aa5f57 　

ISSN： 0004-637X

eISSN： 1538-4357
Three-dimensional Explosion Geometry of Stripped-envelope Core-collapse Supernovae. II. Modeling of Polarization Peer-reviewed

Masaomi Tanaka, Keiichi Maeda, Paolo A. Mazzali, Koji S. Kawabata, Ken'ichi Nomoto

ASTROPHYSICAL JOURNAL　837　(2)　2017/03

DOI： 10.3847/1538-4357/aa6035 　

ISSN： 0004-637X

eISSN： 1538-4357
Broad-lined Supernova 2016coi with a Helium Envelope Peer-reviewed

Masayuki Yamanaka, Tatsuya Nakaoka, Masaomi Tanaka, Keiichi Maeda, Satoshi Honda, Hidekazu Hanayama, Tomoki Morokuma, Masataka Imai, Kenzo Kinugasa, Katsuhiro L. Murata, Takefumi Nishimori, Osamu Hashimoto, Hirotaka Gima, Kensuke Hosoya, Ayano Ito, Mayu Karita, Miho Kawabata, Kumiko Morihana, Yuto Morikawa, Kotone Murakami, Takahiro Nagayama, Tatsuharu Ono, Hiroki Onozato, Yuki Sarugaku, Mitsuteru Sato, Daisuke Suzuki, Jun Takahashi, Masaki Takayama, Hijiri Yaguchi, Hiroshi Akitaya, Yuichiro Asakura, Koji S. Kawabata, Daisuke Kuroda, Daisaku Nogami, Yumiko Oasa, Toshihiro Omodaka, Yoshihiko Saito, Kazuhiro Sekiguchi, Nozomu Tominaga, Makoto Uemura, Makoto Watanabe

The Astrophysical Journal　837　(1)　1　2017/02
Publisher: American Astronomical Society
DOI： 10.3847/1538-4357/aa5f57 　

ISSN： 1538-4357
J-GEM follow-up observations of the gravitational wave source GW151226 Peer-reviewed

Yoshida, Michitoshi, Utsumi, Yousuke, Tominaga, Nozomu, Morokuma, Tomoki, Tanaka, Masaomi, Asakura, Yuichiro, Matsubayashi, Kazuya, Ohta, Kouji, Abe, Fumio, Chimasu, Sho, Furusawa, Hisanori, Itoh, Ryosuke, Itoh, Yoichi, Kanda, Yuka, Kawabata, Koji S, Kawabata, Miho, Koshida, Shintaro, Koshimoto, Naoki, Kuroda, Daisuke, Moritani, Yuki, Motohara, Kentaro, Murata, Katsuhiro L, Nagayama, Takahiro, Nakaoka, Tatsuya, Nakata, Fumiaki, Nishioka, Tsubasa, Saito, Yoshihiko, Terai, Tsuyoshi, Tristram, Paul J, Yanagisawa, Kenshi, Yasuda, Naoki, Doi, Mamoru, Fujisawa, Kenta, Kawachi, Akiko, Kawai, Nobuyuki, Tamura, Yoichi, Uemura, Makoto, Yatsu, Yoichi

Publications of the Astronomical Society of Japan　69　9　2017/02/01

DOI： 10.1093/pasj/psw113 　

ISSN： 2053-051X
SN 2016jhj at redshift 0.34: Extending the Type II supernova Hubble diagram using the standard candle method Peer-reviewed

T. de Jaeger, L. Galbany, A. V. Filippenko, S. González-Gaitán, N. Yasuda, K. Maeda, M. Tanaka, T. Morokuma, T. J. Moriya, N. Tominaga, K. Nomoto, Y. Komiyama, J. P. Anderson, T. G. Brink, R. G. Carlberg, G. Folatelli, M. Hamuy, G. Pignata, W. Zheng

Monthly Notices of the Royal Astronomical Society: Letters　472　(4)　4233-4243　2017
Publisher: Oxford University Press
DOI： 10.1093/mnras/stx2300 　

ISSN： 1745-3933 1745-3925
Properties of X-ray emission of an aspherical shock breakout Peer-reviewed

Ohtani Yukari, Suzuki Akihiro, Shigeyama Toshikazu, Tanaka Masaomi

SUPERNOVA 1987A: 30 YEARS LLATER - COSMIC RAYS AND NUCLEI FROM SUPERNOVAE AND THEIR AFTERMATHS　12　(S331)　51-56　2017

DOI： 10.1017/S1743921317004872 　

ISSN： 1743-9213
Multi-messenger signals from core-collapse supernovae Peer-reviewed

Nakamura Ko, Horiuchi Shunsaku, Tanaka Masaomi, Hayama Kazuhiro, Takiwaki Tomoya, Kotake Kei

LIVES AND DEATH-THROES OF MASSIVE STARS　12　(S329)　428　2017

DOI： 10.1017/S1743921317001193 　

ISSN： 1743-9213
J-GEM Follow-Up Observations of The Gravitational Wave Source GW151226 Peer-reviewed

Michitoshi Yoshida, Yousuke Utsumi, Nozomu Tominaga, Tomoki Morokuma, Masaomi Tanaka, Yuichiro Asakura, Kazuya Matsubayashi, Kouji Ohta, Fumio Abe, Sho Chimasu, Hisanori Furusawa, Ryosuke Itoh, Yoichi Itoh, Yuka Kanda, Koji S. Kawabata, Miho Kawabata, Shintaro Koshida, Naoki Koshimoto, Daisuke Kuroda, Yuki Moritani, Kentaro Motohara, Katsuhiro L. Murata, Takahiro Nagayama, Tatsuya Nakaoka, Fumiaki Nakata, Tsubasa Nishioka, Yoshihiko Saito, Tsuyoshi Terai, Paul J. Tristram, Kenshi Yanagisawa, Naoki Yasuda, Mamoru Doi, Kenta Fujisawa, Akiko Kawachi, Nobuyuki Kawai, Yoichi Tamura, Makoto Uemura, Yoichi Yatsu

PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN　69　(1)　2016/11/05

DOI： 10.1093/pasj/psw113 　

ISSN： 0004-6264
OISTER optical and near-infrared observations of the super-Chandrasekhar supernova candidate SN 2012dn: Dust emission from the circumstellar shell Peer-reviewed

Masayuki Yamanaka, Keiichi Maeda, Masaomi Tanaka, Nozomu Tominaga, Koji S. Kawabata, Katsutoshi Takaki, Miho Kawabata, Tatsuya Nakaoka, Issei Ueno, Hiroshi Akitaya, Takahiro Nagayama, Jun Takahashi, Satoshi Honda, Toshihiro Omodaka, Ryo Miyanoshita, Takashi Nagao, Makoto Watanabe, Mizuki Isogai, Akira Arai, Ryosuke Itoh, Takahiro Ui, Makoto Uemura, Michitoshi Yoshida, Hidekazu Hanayama, Daisuke Kuroda, Nobuharu Ukita, Kenshi Yanagisawa, Hideyuki Izumiura, Yoshihiko Saito, Kazunari Masumoto, Rikako Ono, Ryo Noguchi, Katsura Matsumoto, Daisaku Nogami, Tomoki Morokuma, Yumiko Oasa, Kazuhiro Sekiguchi

PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN　68　(5)　2016/10

DOI： 10.1093/pasj/psw047 　

ISSN： 0004-6264

eISSN： 2053-051X
Multimessenger signals of long-term core-collapse supernova simulations: synergetic observation strategies Peer-reviewed

Ko Nakamura, Shunsaku Horiuchi, Masaomi Tanaka, Kazuhiro Hayama, Tomoya Takiwaki, Kei Kotake

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY　461　(3)　3296-3313　2016/09

DOI： 10.1093/mnras/stw1453 　

ISSN： 0035-8711

eISSN： 1365-2966
The Macronova in GRB 050709 and the GRB-macronova connection Peer-reviewed

Zhi-Ping Jin, Kenta Hotokezaka, Xiang Li, Masaomi Tanaka, Paolo D'Avanzo, Yi-Zhong Fan, Stefano Covino, Da-Ming Wei, Tsvi Piran

NATURE COMMUNICATIONS　7　2016/09

DOI： 10.1038/ncomms12898 　

ISSN： 2041-1723
J-GEM follow-up observations to search for an optical counterpart of the first gravitational wave source GW150914 Peer-reviewed

Morokuma, T, Tanaka, M, Asakura, Y, Abe, F, Tristram, P. J, Utsumi, Y, Doi, M, Fujisawa, K, Itoh, R, Itoh, Y, Kawabata, K. S, Kawai, N, Kuroda, D, Matsubayashi, K, Motohara, K, Murata, K. L, Nagayama, T, Ohta, K, Saito, Y, Tamura, Y, Tominaga, N, Uemura, M, Yanagisawa, K, Yatsu, Y, Yoshida, M

Publications of the Astronomical Society of Japan　68　L9　2016/08/01

DOI： 10.1093/pasj/psw061 　

ISSN： 2053-051X
CONSTRAINING THE AGE AND DISTANCE OF THE GALACTIC SUPERNOVA REMNANT G156.2+5.7 BY H alpha EXPANSION MEASUREMENTS Peer-reviewed

Satoru Katsuda, Masaomi Tanaka, Tomoki Morokuma, Robert Fesen, Dan Milisavljevic

ASTROPHYSICAL JOURNAL　826　(2)　2016/08

DOI： 10.3847/0004-637X/826/2/108 　

ISSN： 0004-637X

eISSN： 1538-4357
MODELS OF KILONOVA/MACRONOVA EMISSION FROM BLACK HOLE-NEUTRON STAR MERGERS Peer-reviewed

Kyohei Kawaguchi, Koutarou Kyutoku, Masaru Shibata, Masaomi Tanaka

ASTROPHYSICAL JOURNAL　825　(1)　2016/07

DOI： 10.3847/0004-637X/825/1/52 　

ISSN： 0004-637X

eISSN： 1538-4357
An effective selection method for low-mass active black holes and first spectroscopic identification Peer-reviewed

Tomoki Morokuma, Nozomu Tominaga, Masaomi Tanaka, Naoki Yasuda, Hisanori Furusawa, Yuki Taniguchi, Takahiro Kato, Ji-an Jiang, Tohru Nagao, Hanindyo Kuncarayakti, Kana Morokuma-Matsui, Hiroyuki Ikeda, Sergei Blinnikov, Ken'ichi Nomoto, Mitsuru Kokubo, Mamoru Doi

PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN　68　(3)　2016/06

DOI： 10.1093/pasj/psw033 　

ISSN： 0004-6264

eISSN： 2053-051X
J-GEM Follow-Up Observations to Search for an Optical Counterpart of The First Gravitational Wave Source GW150914 Peer-reviewed

Tomoki Morokuma, Masaomi Tanaka, Yuichiro Asakura, Fumio Abe, Paul J. Tristram, Yousuke Utsumi, Mamoru Doi, Kenta Fujisawa, Ryosuke Itoh, Yoichi Itoh, Koji S. Kawabata, Nobuyuki Kawai, Daisuke Kuroda, Kazuya Matsubayashi, Kentaro Motohara, Katsuhiro L. Murata, Takahiro Nagayama, Kouji Ohta, Yoshihiko Saito, Yoichi Tamura, Nozomu Tominaga, Makoto Uemura, Kenshi Yanagisawa, Yoichi Yatsu, Michitoshi Yoshida

PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN　68　(4)　2016/05/10

DOI： 10.1093/pasj/psw061 　

ISSN： 0004-6264
RAPIDLY RISING TRANSIENTS FROM THE SUBARU HYPER SUPRIME-CAM TRANSIENT SURVEY Peer-reviewed

Masaomi Tanaka, Nozomu Tominaga, Tomoki Morokuma, Naoki Yasuda, Hisanori Furusawa, Petr V. Baklanov, Sergei I. Blinnikov, Takashi J. Moriya, Mamoru Doi, Ji-an Jiang, Takahiro Kato, Yuki Kikuchi, Hanindyo Kuncarayakti, Tohru Nagao, Ken'ichi Nomoto, Yuki Taniguchi

ASTROPHYSICAL JOURNAL　819　(1)　2016/03

DOI： 10.3847/0004-637X/819/1/5 　

ISSN： 0004-637X

eISSN： 1538-4357
SODIUM ABSORPTION SYSTEMS TOWARD SN Ia 2014J ORIGINATE ON INTERSTELLAR SCALES Peer-reviewed

Maeda, K, Tajitsu, A, Kawabata, K. S, Foley, R. J, Honda, S, Moritani, Y, Tanaka, M, Hashimoto, O, Ishigaki, M, Simon, J. D, Phillips, M. M, Yamanaka, M, Nogami, D, Arai, A, Aoki, W, Nomoto, K, Milisavljevic, D, Mazzali, P. A, Soderberg, A. M, Schramm, M, Sato, B, Harakawa, H, Morrell, N, Arimoto, N

ASTROPHYSICAL JOURNAL　816　(2)　2016/01/10
Publisher: IOP PUBLISHING LTD
DOI： 10.3847/0004-637X/816/2/57 　

ISSN： 0004-637X

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Na I. D absorbing systems toward Type Ia supernovae (SNe Ia) have been intensively studied over the last decade with the aim of finding circumstellar material (CSM), which is an indirect probe of the progenitor system. However, it is difficult to deconvolve CSM components from non-variable, and often dominant, components created by interstellar material (ISM). We present a series of high-resolution spectra of SN. Ia. 2014J from before maximum brightness to greater than or similar to 250. days after maximum brightness. The late-time spectrum provides unique information for determining the origin of the Na I. D absorption systems. The deep late-time observation allows us to probe the environment around the SN at a large scale, extending to greater than or similar to 40 pc. We find that a spectrum of diffuse light in the vicinity, but not directly in the line of sight, of the SN has absorbing systems nearly identical to those obtained for the pure" SN line of sight. Therefore, basically all Na I. D systems seen toward SN. 2014J must originate from foreground material that extends to at least similar to 40 pc in projection and none at the CSM scale. A fluctuation in the column den
GRB 160206A: Kiso/KWFC optical observations. Peer-reviewed

Morokuma} T, Tominaga} N, Tanaka} M, Suzuki} A, Serino} M, Sakamoto} T, Maeda} K

GRB Coordinates Network　19008　1　2016
Kilonova/Macronova Emission from Compact Binary Mergers Peer-reviewed

Masaomi Tanaka

ADVANCES IN ASTRONOMY　2016

DOI： 10.1155/2016/6341974 　

ISSN： 1687-7969

eISSN： 1687-7977
Development of a real-time data processing system for a prototype of the Tomo-e Gozen wide field CMOS camera Peer-reviewed

Ryou Ohsawa, Shigeyuki Sako, Hidenori Takahashi, Yuki Kikuchi, Mamoru Doi, Naoto Kobayashi, Tsutomu Aoki, Ko Arimatsu, Makoto Ichiki, Shiro Ikeda, Yoshifusa Ita, Toshihiro Kasuga, Hideo Kawakita, Mitsuru Kokubo, Hiroyuki Maehara, Noriyuki Matsunaga, Hiroyuki Mito, Kazuma Mitsuda, Takashi Miyata, Kiyoshi Mori, Yuki Mori, Mikio Morii, Tomoki Morokuma, Kentaro Motohara, Yoshikazu Nakada, Shin Ichiro Okumura, Hiroki Onozato, Kentaro Osawa, Yuki Sarugaku, Mikiya Sato, Toshikazu Shigeyama, Takao Soyano, Masaomi Tanaka, Yuki Taniguchi, Ataru Tanikawa, Ken'Ichi Tarusawa, Nozomu Tominaga, Tomonori Totani, Seitaro Urakawa, Fumihiko Usui, Junichi Watanabe, Jumpei Yamaguchi, Makoto Yoshikawa

Proceedings of SPIE - The International Society for Optical Engineering　9913　2016

DOI： 10.1117/12.2231615 　

ISSN： 0277-786X

eISSN： 1996-756X
Development of a prototype of the Tomo-e Gozen wide-field CMOS camera Peer-reviewed

Shigeyuki Sako, Ryou Osawa, Hidenori Takahashi, Yuki Kikuchi, Mamoru Doi, Naoto Kobayashi, Tsutomu Aoki, Ko Arimatsu, Makoto Ichiki, Shiro Ikeda, Yoshifusa Ita, Toshihiro Kasuga, Hideyo Kawakita, Mitsuru Kokubo, Hiroyuki Maehara, Noriyuki Matsunaga, Hiroyuki Mito, Kazuma Mitsuda, Takashi Miyata, Kiyoshi Mori, Yuki Mori, Mikio Morii, Tomoki Morokuma, Kentaro Motohara, Yoshikazu Nakada, Kentaro Osawa, Shin Ichiro Okumura, Hiroki Onozato, Yuki Sarugaku, Mikiya Sato, Toshikazu Shigeyama, Takao Soyano, Masaomi Tanaka, Yuki Taniguchi, Ataru Tanikawa, Ken'Ichi Tarusawa, Nozomu Tominaga, Tomonori Totani, Seitaro Urakawa, Fumihiko Usui, Junichi Watanabe, Jumpei Yamaguchi, Makoto Yoshikawa

Proceedings of SPIE - The International Society for Optical Engineering　9908　2016

DOI： 10.1117/12.2231259 　

ISSN： 0277-786X

eISSN： 1996-756X
Machine-learning selection of optical transients in the Subaru/Hyper Suprime-Cam survey Peer-reviewed

Mikio Morii, Shiro Ikeda, Nozomu Tominaga, Masaomi Tanaka, Tomoki Morokuma, Katsuhiko Ishiguro, Junji Yamato, Naonori Ueda, Naotaka Suzuki, Naoki Yasuda, Naoki Yoshida

Publications of the Astronomical Society of Japan　68　(6)　2016

DOI： 10.1093/pasj/psw096 　

ISSN： 0004-6264

eISSN： 2053-051X
Radiation hydrodynamics simulations of wide-angle outflows from super-critical accretion disks around black holes Peer-reviewed

Katsuya Hashizume, Ken Ohsuga, Tomohisa Kawashima, Masaomi Tanaka

PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN　67　(4)　2015/08

DOI： 10.1093/pasj/psu132 　

ISSN： 0004-6264

eISSN： 2053-051X
KEPLER’SSUPERNOVA: AN OVERLUMINOUS TYPE Ia EVENT INTERACTING WITH A MASSIVE CIRCUMSTELLAR MEDIUM AT A VERY LATE PHASE

Satoru Katsuda, Koji Mori, Keiichi Maeda, Masaomi Tanaka, Katsuji Koyama, Hiroshi Tsunemi, Hiroshi Nakajima, Yoshitomo Maeda, Masanobu Ozaki, Robert Petre

The Astrophysical Journal　2015/07/17

DOI： 10.1088/0004-637x/808/1/49 　

ISSN： 1538-4357
Type IIb Supernova 2013df Entering into an Interaction Phase: A Link between the Progenitor and the Mass Loss Peer-reviewed

K. Maeda, T. Hattori, D. Milisavljevic, G. Folatelli, M.R. Drout, H. Kuncarayakti, R. Margutti, A. Kamble, A. Soderberg, M. Tanaka, M. Kawabata, K.S. Kawabata, M. Yamanaka, K. Nomoto, J.H. Kim, J.D. Simon, M.M. Phillips, J. Parrent, T. Nakaoka, T.J. Moriya, A. Suzuki, K. Takaki, M. Ishigaki, I. Sakon, A. Tajitsu, M. Iye

The Astrophysical Journal　807　(1)　35　2015/07
Publisher: American Astronomical Society
DOI： 10.1088/0004-637X/807/1/35 　

ISSN： 0004-637X
KEPLER'S SUPERNOVA: AN OVERLUMINOUS TYPE Ia EVENT INTERACTING WITH A MASSIVE CIRCUMSTELLAR MEDIUM AT A VERY LATE PHASE Peer-reviewed

Satoru Katsuda, Koji Mori, Keiichi Maeda, Masaomi Tanaka, Katsuji Koyama, Hiroshi Tsunemi, Hiroshi Nakajima, Yoshitomo Maeda, Masanobu Ozaki, Robert Petre

ASTROPHYSICAL JOURNAL　808　(1)　2015/07

DOI： 10.1088/0004-637X/808/1/49 　

ISSN： 0004-637X

eISSN： 1538-4357
OISTER OPTICAL AND NEAR-INFRARED OBSERVATIONS OF TYPE Iax SUPERNOVA 2012Z Peer-reviewed

Masayuki Yamanaka, Keiichi Maeda, Koji S. Kawabata, Masaomi Tanaka, Nozomu Tominaga, Hiroshi Akitaya, Takahiro Nagayama, Daisuke Kuroda, Jun Takahashi, Yoshihiko Saito, Kenshi Yanagisawa, Akihiko Fukui, Ryo Miyanoshita, Makoto Watanabe, Akira Arai, Mizuki Isogai, Takashi Hattori, Hidekazu Hanayama, Ryosuke Itoh, Takahiro Ui, Katsutoshi Takaki, Issei Ueno, Michitoshi Yoshida, Gamal B. Ali, Ahmed Essam, Akihito Ozaki, Hikaru Nakao, Ko Hamamoto, Daisaku Nogami, Tomoki Morokuma, Yumiko Oasa, Hideyuki Izumiura, Kazuhiro Sekiguchi

The Astrophysical Journal　806　(2)　191　2015/06
Publisher: {IOP} Publishing
DOI： 10.1088/0004-637x/806/2/191 　

ISSN： 1538-4357
OISTER OPTICAL AND NEAR-INFRARED OBSERVATIONS OF TYPE IAX SUPERNOVA 2012Z Peer-reviewed

Masayuki Yamanaka, Keiichi Maeda, Koji S. Kawabata, Masaomi Tanaka, Nozomu Tominaga, Hiroshi Akitaya, Takahiro Nagayama, Daisuke Kuroda, Jun Takahashi, Yoshihiko Saito, Kenshi Yanagisawa, Akihiko Fukui, Ryo Miyanoshita, Makoto Watanabe, Akira Arai, Mizuki Isogai, Takashi Hattori, Hidekazu Hanayama, Ryosuke Itoh, Takahiro Ui, Katsutoshi Takaki, Issei Ueno, Michitoshi Yoshida, Gamal B. Ali, Ahmed Essam, Akihito Ozaki, Hikaru Nakao, Ko Hamamoto, Daisaku Nogami, Tomoki Morokuma, Yumiko Oasa, Hideyuki Izumiura, Kazuhiro Sekiguchi

ASTROPHYSICAL JOURNAL　806　(2)　2015/06

DOI： 10.1088/0004-637X/806/2/191 　

ISSN： 0004-637X

eISSN： 1538-4357
Thirty Meter Telescope Detailed Science Case: 2015 Peer-reviewed

Warren Skidmore, Ian Dell'Antonio, Misato Fukugawa, Aruna Goswami, Lei Hao, David Jewitt, Greg Laughlin, Charles Steidel, Paul Hickson, Luc Simard, Matthias Schöck, Tommaso Treu, Judith Cohen, G. C. Anupama, Mark Dickinson, Fiona Harrison, Tadayuki Kodama, Jessica R. Lu, Bruce Macintosh, Matt Malkan, Shude Mao, Norio Narita, Tomohiko Sekiguchi, Annapurni Subramaniam, Masaomi Tanaka, Feng Tian, Michael A'Hearn, Masayuki Akiyama, Babar Ali, Wako Aoki, Manjari Bagchi, Aaron Barth, Varun Bhalerao, Marusa Bradac, James Bullock, Adam J. Burgasser, Scott Chapman, Ranga-Ram Chary, Masashi Chiba, Michael Cooper, Asantha Cooray, Ian Crossfield, Thayne Currie, Mousumi Das, G. C. Dewangan, Richard de Grijs, Tuan Do, Subo Dong, Jarah Evslin, Taotao Fang, Xuan Fang, Christopher Fassnacht, Leigh Fletcher, Eric Gaidos, Roy Gal, Andrea Ghez, Mauro Giavalisco, Carol A. Grady, Thomas Greathouse, Rupjyoti Gogoi, Puragra Guhathakurta, Luis Ho, Priya Hasan, Gregory J. Herczeg, Mitsuhiko Honda, Masa Imanishi, Hanae Inami, Masanori Iye, Jason Kalirai, U. S. Kamath, Stephen Kane, Nobunari Kashikawa, Mansi Kasliwal, Vishal Kasliwal, Evan Kirby, Quinn M. Konopacky, Sebastien Lepine, Di Li, Jianyang Li, Junjun Liu, Michael C. Liu, Enrigue Lopez-Rodriguez, Jennifer Lotz, Philip Lubin, Lucas Macri, Keiichi Maeda, Franck Marchis, Christian Marois, Alan Marscher, Crystal Martin, Taro Matsuo, Claire Max, Alan McConnachie, Stacy McGough, Carl Melis, Leo Meyer, Michael Mumma, Takayuki Muto, Tohru Nagao, Joan R. Najita, Julio Navarro, Michael Pierce, Jason X. Prochaska, Masamune Oguri, Devendra K. Ojha, Yoshiko K. Okamoto, Glenn Orton, Angel Otarola, Masami Ouchi, Chris Packham, Deborah L. Padgett, Shashi Bhushan Pandey, Catherine Pilachowsky, Klaus M. Pontoppidan, Joel Primack, Shalima Puthiyaveettil, Enrico Ramirez-Ruiz, Naveen Reddy, Michael Rich, Matthew J. Richter, James Schombert, Anjan Ananda Sen, Jianrong Shi, Kartik Sheth, R. Srianand, Jonathan C. Tan, Masayuki Tanaka, Angelle Tanner, Nozomu Tominaga, David Tytler, Vivian U, Lingzhi Wang, Xiaofeng Wang, Yiping Wang, Gillian Wilson, Shelley Wright, Chao Wu, Xufeng Wu, Renxin Xu, Toru Yamada, Bin Yang, Gongbo Zhao, Hongsheng Zhao

2015/05/05

DOI： 10.1088/1674-4527/15/12/001 　

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The TMT Detailed Science Case describes the transformational science that the Thirty Meter Telescope will enable. Planned to begin science operations in 2024, TMT will open up opportunities for revolutionary discoveries in essentially every field of astronomy, astrophysics and cosmology, seeing much fainter objects much more clearly than existing telescopes. Per this capability, TMT's science agenda fills all of space and time, from nearby comets and asteroids, to exoplanets, to the most distant galaxies, and all the way back to the very first sources of light in the Universe. More than 150 astronomers from within the TMT partnership and beyond offered input in compiling the new 2015 Detailed Science Case. The contributing astronomers represent the entire TMT partnership, including the California Institute of Technology (Caltech), the Indian Institute of Astrophysics (IIA), the National Astronomical Observatories of the Chinese Academy of Sciences (NAOC), the National Astronomical Observatory of Japan (NAOJ), the University of California, the Association of Canadian Universities for Research in Astronomy (ACURA) and US associate partner, the Association of Universities for Research in Astronomy (AURA).
Kiso Supernova Survey (KISS): Survey strategy Peer-reviewed

Tomoki Morokuma, Nozomu Tominaga, Masaomi Tanaka, Kensho Mori, Emiko Matsumoto, Yuki Kikuchi, Takumi Shibata, Shigeyuki Sako, Tsutomu Aoki, Mamoru Doi, Naoto Kobayashi, Hiroyuki Maehara, Noriyuki Matsunaga, Hiroyuki Mito, Takashi Miyata, Yoshikazu Nakada, Takao Soyano, Ken'ichi Tarusawa, Satoshi Miyazaki, Fumiaki Nakata, Norio Okada, Yuki Sarugaku, Michael W. Richmond, Hiroshi Akitaya, Greg Aldering, Ko Arimatsu, Carlos Contreras, Takashi Hortiuchi, Eric Y. Hsiao, Ryosuke Itoh, Ikuru Iwata, Koji S. Kawabata, Nobuyuki Kawai, Yutaro Kitagawa, Mitsuru Kokubo, Daisuke Kuroda, Paolo Mazzali, Toru Misawa, Yuki Moritani, Nidia Morrell, Rina Okamoto, Nikolay Pavlyuk, Mark M. Phillips, Elena Pian, Devendra Sahu, Yoshihiko Saito, Kei Sano, Maximilian D. Stritzinger, Yutaro Tachibana, Francesco Taddia, Katsutoshi Takaki, Ken Tateuchi, Akihiko Tomita, Dmitry Tsvetkov, Takahiro Ui, Nobuharu Ukita, Yuji Urata, Emma S. Walker, Taketoshi Yoshii

PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN　66　(6)　2014/12

DOI： 10.1093/pasj/psu105 　

ISSN： 0004-6264

eISSN： 2053-051X
OPTICAL AND NEAR-INFRARED POLARIMETRY OF HIGHLY REDDENED Type Ia SUPERNOVA 2014J: PECULIAR PROPERTIES OF DUST IN M82 Peer-reviewed

K. S. Kawabata, H. Akitaya, M. Yamanaka, R. Itoh, K. Maeda, Y. Moritani, T. Ui, M. Kawabata, K. Mori, D. Nogami, K. Nomoto, N. Suzuki, K. Takaki, M. Tanaka, I. Ueno, S. Chiyonobu, T. Harao, R. Matsui, H. Miyamoto, O. Nagae, A. Nakashima, H. Nakaya, Y. Ohashi, T. Ohsugi, T. Komatsu, K. Sakimoto, M. Sasada, H. Sato, H. Tanaka, T. Urano, T. Yamashita, M. Yoshida, A. Arai, N. Ebisuda, Y. Fukazawa, A. Fukui, O. Hashimoto, S. Honda, H. Izumiura, Y. Kanda, K. Kawaguchi, N. Kawai, D. Kuroda, K. Masumoto, T. Nakaoka, K. Takata, M. Uemura, K. Yanagisawa

ASTROPHYSICAL JOURNAL LETTERS　795　(1)　L4　2014/11

DOI： 10.1088/2041-8205/795/1/L4 　

ISSN： 2041-8205

eISSN： 2041-8213
The red supergiant and supernova rate problems: implications for core-collapse supernova physics Peer-reviewed

S. Horiuchi, K. Nakamura, T. Takiwaki, K. Kotake, M. Tanaka

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY　445　(1)　L99-L103　2014/11

DOI： 10.1093/mnrasl/slu146 　

ISSN： 0035-8711

eISSN： 1365-2966
DISCOVERY OF DRAMATIC OPTICAL VARIABILITY IN SDSS J1100+4421: A PECULIAR RADIO-LOUD NARROW-LINE SEYFERT 1 GALAXY? Peer-reviewed

Masaomi Tanaka, Tomoki Morokuma, Ryosuke Itoh, Hiroshi Akitaya, Nozomu Tominaga, Yoshihiko Saito, Lukasz Stawarz, Yasuyuki T. Tanaka, Poshak Gandhi, Gamal Ali, Tsutomu Aoki, Carlos Contreras, Mamoru Doi, Ahmad Essam, Gamal Hamed, Eric Y. Hsiao, Ikuru Iwata, Koji S. Kawabata, Nobuyuki Kawai, Yuki Kikuchi, Naoto Kobayashi, Daisuke Kuroda, Hiroyuki Maehara, Emiko Matsumoto, Paolo A. Mazzali, Takeo Minezaki, Hiroyuki Mito, Takashi Miyata, Satoshi Miyazaki, Kensho Mori, Yuki Moritani, Kana Morokuma-Matsui, Nidia Morrell, Tohru Nagao, Yoshikazu Nakada, Fumiaki Nakata, Chinami Noma, Ken Ohsuga, Norio Okada, Mark M. Phillips, Elena Pian, Michael W. Richmond, Devendra Sahu, Shigeyuki Sako, Yuki Sarugaku, Takumi Shibata, Takao Soyano, Maximilian D. Stritzinger, Yutaro Tachibana, Francesco Taddia, Katsutoshi Takaki, Ali Takey, Ken'ichi Tarusawa, Takahiro Ui, Nobuharu Ukita, Yuji Urata, Emma S. Walker, Taketoshi Yoshii

ASTROPHYSICAL JOURNAL LETTERS　793　(2)　2014/10

DOI： 10.1088/2041-8205/793/2/L26 　

ISSN： 2041-8205

eISSN： 2041-8213
The red supergiant and supernova rate problems: implications for core-collapse supernova physics

Shunsaku Horiuchi, Ko Nakamura, Tomoya Takiwaki, Kei Kotake, Masaomi Tanaka

MNRASL 445, L99-L103 (2014)　445　(1)　L99-L103　2014/08/30

DOI： 10.1093/mnrasl/slu146 　

ISSN： 1745-3933 1745-3925

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Mapping supernovae to their progenitors is fundamental to understanding the collapse of massive stars. We investigate the red supergiant problem, which concerns why red supergiants with masses $\sim16$-$30 M_\odot$ have not been identified as progenitors of Type IIP supernovae, and the supernova rate problem, which concerns why the observed cosmic supernova rate is smaller than the observed cosmic star formation rate. We find key physics to solving these in the compactness parameter, which characterizes the density structure of the progenitor. If massive stars with compactness above $\xi_{2.5} \sim 0.2$ fail to produce canonical supernovae, (i) stars in the mass range $16$-$30 M_\odot$ populate an island of stars that have high $\xi_{2.5}$ and do not produce canonical supernovae, and (ii) the fraction of such stars is consistent with the missing fraction of supernovae relative to star formation. We support this scenario with a series of two- and three-dimensional radiation hydrodynamics core-collapse simulations. Using more than 300 progenitors covering initial masses $10.8$-$75 M_\odot$ and three initial metallicities, we show that high compactness is conducive to failed explosions. We then argue that a critical compactness of $\sim 0.2$ as the divide between successful and failed explosions is consistent with state-of-the-art three-dimensional core-collapse simulations. Our study implies that numerical simulations of core collapse need not produce robust explosions in a significant fraction of compact massive star initial conditions.
RANDOM WALKS AND EFFECTIVE OPTICAL DEPTH IN RELATIVISTIC FLOW Peer-reviewed

Sanshiro Shibata, Nozomu Tominaga, Masaomi Tanaka

ASTROPHYSICAL JOURNAL LETTERS　787　(1)　2014/05

DOI： 10.1088/2041-8205/787/1/L4 　

ISSN： 2041-8205

eISSN： 2041-8213
EARLY-PHASE PHOTOMETRY AND SPECTROSCOPY OF TRANSITIONAL TYPE Ia SN 2012ht: DIRECT CONSTRAINT ON THE RISE TIME Peer-reviewed

Masayuki Yamanaka, Keiichi Maeda, Miho Kawabata, Masaomi Tanaka, Katsutoshi Takaki, Issei Ueno, Kazunari Masumoto, Koji S. Kawabata, Ryosuke Itoh, Yuki Moritani, Hiroshi Akitaya, Akira Arai, Satoshi Honda, Koichi Nishiyama, Fujio Kabashima, Katsura Matsumoto, Daisaku Nogami, Michitoshi Yoshida

ASTROPHYSICAL JOURNAL LETTERS　782　(2)　2014/02

DOI： 10.1088/2041-8205/782/2/L35 　

ISSN： 2041-8205

eISSN： 2041-8213
RADIOACTIVELY POWERED EMISSION FROM BLACK HOLE-NEUTRON STAR MERGERS Peer-reviewed

Masaomi Tanaka, Kenta Hotokezaka, Koutarou Kyutoku, Shinya Wanajo, Kenta Kiuchi, Yuichiro Sekiguchi, Masaru Shibata

ASTROPHYSICAL JOURNAL　780　(1)　2014/01

DOI： 10.1088/0004-637X/780/1/31 　

ISSN： 0004-637X

eISSN： 1538-4357
Light curve modeling of superluminous supernovae Peer-reviewed

Takashi Moriya, Sergei I. Blinnikov, Nozomu Tominaga, Naoki Yoshida, Masaomi Tanaka, Keiichi Maeda, Ken'ichi Nomoto

Proceedings of the International Astronomical Union　9　(296)　86-89　2014

DOI： 10.1017/S1743921313009277 　

ISSN： 1743-9213 1743-9221
Detectability of high-redshift superluminous supernovae with upcoming optical and near-infrared surveys - II. Beyond z=6 Peer-reviewed

Masaomi Tanaka, Takashi J. Moriya, Naoki Yoshida

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY　435　(3)　2483-2493　2013/11

DOI： 10.1093/mnras/stt1469 　

ISSN： 0035-8711

eISSN： 1365-2966
PROGENITOR MODELS OF THE ELECTROMAGNETIC TRANSIENT ASSOCIATED WITH THE SHORT GAMMA RAY BURST 130603B Peer-reviewed

Kenta Hotokezaka, Koutarou Kyutoku, Masaomi Tanaka, Kenta Kiuchi, Yuichiro Sekiguchi, Masaru Shibata, Shinya Wanajo

ASTROPHYSICAL JOURNAL LETTERS　778　(1)　2013/11

DOI： 10.1088/2041-8205/778/1/L16 　

ISSN： 2041-8205

eISSN： 2041-8213
Radiative transfer simulations of neutron star merger ejecta Peer-reviewed

Masaomi Tanaka, Kenta Hotokezaka

Astrophysical Journal　775　(2)　2013/10/01

DOI： 10.1088/0004-637X/775/2/113 　

ISSN： 1538-4357 0004-637X
A LUMINOUS AND FAST-EXPANDING TYPE Ib SUPERNOVA SN 2012au Peer-reviewed

Katsutoshi Takaki, Koji S. Kawabata, Masayuki Yamanaka, Keiichi Maeda, Masaomi Tanaka, Hiroshi Akitaya, Yasushi Fukazawa, Ryosuke Itoh, Kenzo Kinugasa, Yuki Moritani, Takashi Ohsugi, Mahito Sasada, Makoto Uemura, Issei Ueno, Takahiro Ui, Takeshi Urano, Michitoshi Yoshida, Kenichi Nomoto

ASTROPHYSICAL JOURNAL LETTERS　772　(2)　2013/08

DOI： 10.1088/2041-8205/772/2/L17 　

ISSN： 2041-8205
The very energetic, broad-lined Type Ic supernova 2010ah (PTF10bzf) in the context of GRB/SNe Peer-reviewed

Paolo A. Mazzali, Emma S. Walker, Elena Pian, Masaomi Tanaka, Alessandra Corsi, Takashi Hattori, Avishay Gal-Yam

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY　432　(3)　2463-2473　2013/07

DOI： 10.1093/mnras/stt605 　

ISSN： 0035-8711

eISSN： 1365-2966
SN 2009js at the crossroads between normal and subluminous type IIP supernovae: Optical and mid-infrared evolution Peer-reviewed

P. Gandhi, M. Yamanaka, M. Tanaka, T. Nozawa, K. S. Kawabata, I. Saviane, K. Maeda, T. J. Moriya, T. Hattori, M. Sasada, R. Itoh

Astrophysical Journal　767　(2)　2013/04/20
Publisher: Institute of Physics Publishing
DOI： 10.1088/0004-637X/767/2/166 　

ISSN： 1538-4357 0004-637X
EARLY ULTRAVIOLET/OPTICAL EMISSION OF THE TYPE Ib SN 2008D Peer-reviewed

Melina C. Bersten, Masaomi Tanaka, Nozomu Tominaga, Omar G. Benvenuto, Ken'ichi Nomoto

ASTROPHYSICAL JOURNAL　767　(2)　2013/04

DOI： 10.1088/0004-637X/767/2/143 　

ISSN： 0004-637X
Light-Echo Spectrum Reveals the Type of Tycho Brahe's 1572 Supernova Peer-reviewed

T. Usuda, O. Krause, M. Tanaka, T. Hattori, M. Goto, S. M. Birkmann, K. Nomoto

BINARY PATHS TO TYPE IA SUPERNOVAE EXPLOSIONS　(281)　335-+　2013

DOI： 10.1017/S1743921312015323 　

ISSN： 1743-9213
Light-curve modelling of superluminous supernova 2006gy: collision between supernova ejecta and a dense circumstellar medium Peer-reviewed

Takashi J. Moriya, Sergei I. Blinnikov, Nozomu Tominaga, Naoki Yoshida, Masaomi Tanaka, Keiichi Maeda, Ken'ichi Nomoto

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY　428　(2)　1020-1035　2013/01

DOI： 10.1093/mnras/sts075 　

ISSN： 0035-8711
The optical SN2012bz associated with the long GRB120422A Peer-reviewed

A. Melandri, E. Pian, P. Ferrero, V. D'Elia, E. S. Walker, G. Ghirlanda, S. Covino, L. Amati, P. D'Avanzo, P. A. Mazzali, M. Della Valle, C. Guidorzi, L. A. Antonelli, M. G. Bernardini, D. Bersier, F. Bufano, S. Campana, A. J. Castro-Tirado, G. Chincarini, J. Deng, A. V. Filippenko, D. Fugazza, G. Ghisellini, C. Kouveliotou, K. Maeda, G. Marconi, N. Masetti, K. Nomoto, E. Palazzi, F. Patat, S. Piranomonte, R. Salvaterra, I. Saviane, R. L. C. Starling, G. Tagliaferri, M. Tanaka, S. D. Vergani

ASTRONOMY & ASTROPHYSICS　547　2012/11

DOI： 10.1051/0004-6361/201219879 　

ISSN： 0004-6361
A THEORETICAL COLOR-VELOCITY CORRELATION FOR SUPERNOVAE ASSOCIATED WITH GAMMA-RAY BURSTS Peer-reviewed

Sharon Rapoport, Stuart A. Sim, Keiichi Maeda, Masaomi Tanaka, Markus Kromer, Brian P. Schmidt, Ken'ichi Nomoto

ASTROPHYSICAL JOURNAL　759　(1)　2012/11

DOI： 10.1088/0004-637X/759/1/38 　

ISSN： 0004-637X
UNUSUAL LONG AND LUMINOUS OPTICAL TRANSIENT IN THE SUBARU DEEP FIELD Peer-reviewed

Yuji Urata, Patrick P. Tsai, Kuiyun Huang, Tomoki Morokuma, Naoki Yasuda, Masaomi Tanaka, Kentaro Motohara, Masao Hayashi, Nobunari Kashikawa, Chun Ly, Matthew A. Malkan

ASTROPHYSICAL JOURNAL LETTERS　760　(1)　2012/11

DOI： 10.1088/2041-8205/760/1/L11 　

ISSN： 2041-8205

eISSN： 2041-8213
SUPER-CHANDRASEKHAR-MASS LIGHT CURVE MODELS FOR THE HIGHLY LUMINOUS TYPE Ia SUPERNOVA 2009dc Peer-reviewed

Yasuomi Kamiya, Masaomi Tanaka, Ken'ichi Nomoto, Sergei I. Blinnikov, Elena I. Sorokina, Tomoharu Suzuki

ASTROPHYSICAL JOURNAL　756　(2)　2012/09

DOI： 10.1088/0004-637X/756/2/191 　

ISSN： 0004-637X
THE HIGHLY ENERGETIC EXPANSION OF SN 2010bh ASSOCIATED WITH GRB 100316D Peer-reviewed

Filomena Bufano, Elena Pian, Jesper Sollerman, Stefano Benetti, Giuliano Pignata, Stefano Valenti, Stefano Covino, Paolo D'Avanzo, Daniele Malesani, Enrico Cappellaro, Massimo Della Valle, Johan Fynbo, Jens Hjorth, Paolo A. Mazzali, Daniel E. Reichart, Rhaana L. C. Starling, Massimo Turatto, Susanna D. Vergani, Klass Wiersema, Lorenzo Amati, David Bersier, Sergio Campana, Zach Cano, Alberto J. Castro-Tirado, Guido Chincarini, Valerio D'Elia, Antonio de Ugarte Postigo, Jinsong Deng, Patrizia Ferrero, Alexei V. Filippenko, Paolo Goldoni, Javier Gorosabel, Jochen Greiner, Francois Hammer, Pall Jakobsson, Lex Kaper, Koji S. Kawabata, Sylvio Klose, Andrew J. Levan, Keiichi Maeda, Nicola Masetti, Bo Milvang-Jensen, Felix I. Mirabel, Palle Moller, Ken'ichi Nomoto, Eliana Palazzi, Silvia Piranomonte, Ruben Salvaterra, Giulia Stratta, Gianpiero Tagliaferri, Masaomi Tanaka, Nial R. Tanvir, Ralph A. M. J. Wijers

ASTROPHYSICAL JOURNAL　753　(1)　2012/07

DOI： 10.1088/0004-637X/753/1/67 　

ISSN： 0004-637X

eISSN： 1538-4357
THREE-DIMENSIONAL EXPLOSION GEOMETRY OF STRIPPED-ENVELOPE CORE-COLLAPSE SUPERNOVAE. I. SPECTROPOLARIMETRIC OBSERVATIONS Peer-reviewed

Masaomi Tanaka, Koji S. Kawabata, Takashi Hattori, Paolo A. Mazzali, Kentaro Aoki, Masanori Iye, Keiichi Maeda, Ken'ichi Nomoto, Elena Pian, Toshiyuki Sasaki, Masayuki Yamanaka

ASTROPHYSICAL JOURNAL　754　(1)　2012/07

DOI： 10.1088/0004-637X/754/1/63 　

ISSN： 0004-637X
Detectability of high-redshift superluminous supernovae with upcoming optical and near-infrared surveys Peer-reviewed

Masaomi Tanaka, Takashi J. Moriya, Naoki Yoshida, Ken'ichi Nomoto

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY　422　(3)　2675-2684　2012/05

DOI： 10.1111/j.1365-2966.2012.20833.x 　

ISSN： 0035-8711

eISSN： 1365-2966
Elemental abundances in the possible type Ia supernova remnant G344.7-0.1 Peer-reviewed

H. Yamaguchi, M. Tanaka, K. Maeda, P. O. Slane, A. Foster, R. K. Smith, S. Katsuda, R. Yoshii

Astrophysical Journal　749　(2)　2012/04/20
Publisher: Institute of Physics Publishing
DOI： 10.1088/0004-637X/749/2/137 　

ISSN： 1538-4357 0004-637X
A SEARCH FOR INFRARED EMISSION FROM CORE-COLLAPSE SUPERNOVAE AT THE TRANSITIONAL PHASE Peer-reviewed

Masaomi Tanaka, Takaya Nozawa, Itsuki Sakon, Takashi Onaka, Ko Arimatsu, Ryo Ohsawa, Keiichi Maeda, Takehiko Wada, Hideo Matsuhara, Hidehiro Kaneda

ASTROPHYSICAL JOURNAL　749　(2)　2012/04

DOI： 10.1088/0004-637X/749/2/173 　

ISSN： 0004-637X

eISSN： 1538-4357
Late-Phase Observations of a Super-Chandrasekhar SN Ia Peer-reviewed

M. Yamanaka, K. S. Kawabata, K. Maeda, M. Tanaka, M. Yoshida, T. Hattori, K. Nomoto, T. Komatsu, T. Okushima

GALACTIC ARCHAEOLOGY: NEAR-FIELD COSMOLOGY AND THE FORMATION OF THE MILKY WAY　458　49-+　2012
Type IIn superluminous supernovae from collision of supernova ejecta and dense circumstellar medium Peer-reviewed

Moriya} T.~J, Blinnikov} S.~I, Tominaga} N, Yoshida} N, Tanaka} M, Maeda} K, Nomoto} K

American Institute of Physics Conference Series　1480　391-393　2012

DOI： 10.1063/1.4754397 　
UNUSUAL LONG AND LUMINOUS OPTICAL TRANSIENT IN THE SUBARU DEEP FIELD Peer-reviewed

Urata, Yuji, Tsai, Patrick P., Huang, Kuiyun, Morokuma, Tomoki, Yasuda, Naoki, Tanaka, Masaomi, Motohara, Kentaro, Hayashi, Masao, Kashikawa, Nobunari, Ly, Chun, Malkan, Matthew A.

Astrophysical Journal Letters　760　(1)　L11　2012

DOI： 10.1088/2041-8205/760/1/L11 　

ISSN： 2041-8213
UNBURNED MATERIAL IN THE EJECTA OF TYPE Ia SUPERNOVAE Peer-reviewed

Gaston Folatelli, M. M. Phillips, Nidia Morrell, Masaomi Tanaka, Keiichi Maeda, Ken'ichi Nomoto, Maximilian Stritzinger, Christopher R. Burns, Mario Hamuy, Paolo Mazzali, Luis Boldt, Abdo Campillay, Carlos Contreras, Sergio Gonzalez, Miguel Roth, Francisco Salgado, W. L. Freedman, Barry F. Madore, S. E. Persson, Nicholas B. Suntzeff

ASTROPHYSICAL JOURNAL　745　(1)　2012/01

DOI： 10.1088/0004-637X/745/1/74 　

ISSN： 0004-637X
Subaru Spectropolarimetry of Supernovae Peer-reviewed

Masaomi Tanaka, Koji S. Kawabata, Takashi Hattori, Kentaro Aoki, Masanori Iye, Keiichi Maeda, Paolo A. Mazzali, Ken'ichi Nomoto, Elena Pian, Toshiyuki Sasaki, Masayuki Yamanaka

STELLAR POLARIMETRY: FROM BIRTH TO DEATH　1429　208-211　2012

DOI： 10.1063/1.3701927 　

ISSN： 0094-243X
Spectropolarimetry of Type Ibc Supernovae Peer-reviewed

Masaomi Tanaka, Koji S. Kawabata, Takashi Hattori, Paolo A. Mazzali, Kentaro Aoki, Masanori Iye, Keiichi Maeda, Ken'ichi Nomoto, Elena Pian, Toshiyuki Sasaki, Masayuki Yamanaka

DEATH OF MASSIVE STARS: SUPERNOVAE AND GAMMA-RAY BURSTS　(279)　138-141　2012

DOI： 10.1017/S1743921312012823 　

ISSN： 1743-9213
Gamma-Ray Bursts and magnetar-forming Supernovae Peer-reviewed

Ken'ichi Nomoto, Keiichi Maeda, Masaomi Tanaka, Tomoharu Suzuki

ASTROPHYSICS AND SPACE SCIENCE　336　(1)　129-137　2011/11

DOI： 10.1007/s10509-011-0658-1 　

ISSN： 0004-640X
FORMATION OF DUST IN THE EJECTA OF TYPE Ia SUPERNOVAE Peer-reviewed

Takaya Nozawa, Keiichi Maeda, Takashi Kozasa, Masaomi Tanaka, Ken'ichi Nomoto, Hideyuki Umeda

ASTROPHYSICAL JOURNAL　736　(1)　2011/07

DOI： 10.1088/0004-637X/736/1/45 　

ISSN： 0004-637X
Abundance stratification in Type Ia supernovae - III. The normal SN 2003du Peer-reviewed

Masaomi Tanaka, Paolo A. Mazzali, Vallery Stanishev, Immanuel Maurer, Wolfgang E. Kerzendorf, Ken'ichi Nomoto

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY　410　(3)　1725-1738　2011/02

DOI： 10.1111/j.1365-2966.2010.17556.x 　

ISSN： 0035-8711

eISSN： 1365-2966
Is there a mildly relativistic jet in SN2007gr? Peer-reviewed

Z. Paragi, A. J. Van Der Horst, M. Tanaka, G. B. Taylor, C. Kouveliotou, J. Granot, E. Ramirez-Ruiz, Y. Pidopryhora, S. Bourke, R. M. Campbell, M. A. Garrett, H. J. Van Langevelde

Proceedings of the International Astronomical Union　6　(275)　319-320　2010/09

DOI： 10.1017/S1743921310016297 　

ISSN： 1743-9213 1743-9221
FALLBACK SUPERNOVAE: A POSSIBLE ORIGIN OF PECULIAR SUPERNOVAE WITH EXTREMELY LOW EXPLOSION ENERGIES Peer-reviewed

Takashi Moriya, Nozomu Tominaga, Masaomi Tanaka, Ken'ichi Nomoto, Daniel N. Sauer, Paolo A. Mazzali, Keiichi Maeda, Tomoharu Suzuki

ASTROPHYSICAL JOURNAL　719　(2)　1445-1453　2010/08

DOI： 10.1088/0004-637X/719/2/1445 　

ISSN： 0004-637X
An asymmetric explosion as the origin of spectral evolution diversity in type Ia supernovae Peer-reviewed

K. Maeda, S. Benetti, M. Stritzinger, F. K. Roepke, G. Folatelli, J. Sollerman, S. Taubenberger, K. Nomoto, G. Leloudas, M. Hamuy, M. Tanaka, P. A. Mazzali, N. Elias-Rosa

NATURE　466　(7302)　82-85　2010/07

DOI： 10.1038/nature09122 　

ISSN： 0028-0836
A CORE-COLLAPSE SUPERNOVA MODEL FOR THE EXTREMELY LUMINOUS TYPE Ic SUPERNOVA 2007BI: AN ALTERNATIVE TO THE PAIR-INSTABILITY SUPERNOVA MODEL Peer-reviewed

Takashi Moriya, Nozomu Tominaga, Masaomi Tanaka, Keiichi Maeda, Ken'ichi Nomoto

ASTROPHYSICAL JOURNAL LETTERS　717　(2)　L83-L86　2010/07

DOI： 10.1088/2041-8205/717/2/L83 　

ISSN： 2041-8205

eISSN： 2041-8213
A massive star origin for an unusual helium-rich supernova in an elliptical galaxy Peer-reviewed

Kawabata, K. S, Maeda, K, Nomoto, K, Taubenberger, S, Tanaka, M, Deng, J, Pian, E, Hattori, T, Itagaki, K

NATURE　465　(7296)　326-328　2010/05/20
Publisher: NATURE PUBLISHING GROUP
DOI： 10.1038/nature09055 　

ISSN： 0028-0836

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The unusual helium-rich (type Ib) supernova SN 2005E is distinguished from all supernovae hitherto observed by its faint and rapidly fading light curve, prominent calcium lines in late-phase spectra and lack of any mark of recent star formation near the supernova location. These properties are claimed(1) to be explained by a helium detonation in a thin surface layer of an accreting white dwarf. Here we report that the observed properties of SN 2005cz, which appeared in an elliptical galaxy, resemble those of SN 2005E. We argue that these properties are best explained by a core-collapse supernova at the low-mass end (8-12 solar masses) of the range of massive stars that explode(2). Such a low-mass progenitor lost its hydrogen-rich envelope through binary interaction, had very thin oxygen-rich and silicon-rich layers above the collapsing core, and accordingly ejected a very small amount of radioactive (56)Ni and oxygen. Although the host galaxy NGC 4589 is an elliptical, some studies have revealed evidence of recent star-formation activity(3), consistent with the core-collapse model.
SPECTROPOLARIMETRY OF EXTREMELY LUMINOUS TYPE Ia SUPERNOVA 2009dc: NEARLY SPHERICAL EXPLOSION OF SUPER-CHANDRASEKHAR MASS WHITE DWARF Peer-reviewed

Masaomi Tanaka, Koji S. Kawabata, Masayuki Yamanaka, Keiichi Maeda, Takashi Hattori, Kentaro Aoki, Ken'ichi Nomoto, Masanori Iye, Toshiyuki Sasaki, Paolo A. Mazzali, Elena Pian

ASTROPHYSICAL JOURNAL　714　(2)　1209-1216　2010/05

DOI： 10.1088/0004-637X/714/2/1209 　

ISSN： 0004-637X
Hypernovae, gamma-ray bursts, and first stars Peer-reviewed

Ken'ichi Nomoto, Masaomi Tanaka, Nozomu Tominaga, Keiichi Maeda

NEW ASTRONOMY REVIEWS　54　(3-6)　191-200　2010/03

DOI： 10.1016/j.newar.2010.09.022 　

ISSN： 1387-6473
Unusual supernovae, Pop III Gamma-Ray Bursts, and first chemical enrichment

Ken'ichi Nomoto, Takashi Moriya, Masaomi Tanaka, Keiichi Maeda, Nozomu Tominaga, Tomoharu Suzuki

Proceedings of Science　2010

ISSN： 1824-8039
Observations of the Optical Transient in NGC 300 with AKARI/IRC: Possibilities of Asymmetric Dust Formation Peer-reviewed

Ohsawa} R, Sakon} I, Onaka} T, Tanaka} M, Moriya} T, Nozawa} T, Maeda} K, Nomoto} K, Tominaga} N, Usui} F, Matsuhara} H, Nakagawa} T, Murakami} H

\apj　718　(2)　1456-1459　2010

DOI： 10.1088/0004-637X/718/2/1456 　

ISSN： 0004-637X

eISSN： 1538-4357
Hypernova and Gamma-Ray Bursts Peer-reviewed

Nomoto} K, Moriya} T, Tanaka} M, Maeda} K, Tominaga} N, Suzuki} T

Nuclei in the Cosmos　30　2010
Faint Core-Collapse Supernovae with Fallback Peer-reviewed

Moriya Takashi, Tominaga Nozomu, Tanaka Masaomi, Nomoto Ken'ichi, Sauer Daniel N, Mazzali Paolo A, Maeda Keiichi, Suzuki Tomoharu

DECIPHERING THE ANCIENT UNIVERSE WITH GAMMA-RAY BURSTS　1279　224-+　2010

DOI： 10.1063/1.3509269 　

ISSN： 0094-243X
Similarity and difference in GRB-associated SN Ic 1998bw and other type Ib/c supernovae Peer-reviewed

Maeda Keiichi, Kawabata Koji, Tanaka Masaomi, Mazzali Paolo A, Nomoto Ken'ichi

DECIPHERING THE ANCIENT UNIVERSE WITH GAMMA-RAY BURSTS　1279　366-+　2010

DOI： 10.1063/1.3509313 　

ISSN： 0094-243X
Multi-Dimensional Explosion Geometry of Supernovae: Spectropolarimetric Study with Subaru Peer-reviewed

Tanaka Masaomi, Kawabata Koji S, Hattori Takashi, Aoki Kentaro, Iye Masanori, Maeda Keiichi, Mazzali Paolo A, Nomoto Ken'ichi, Pian Elena, Sasaki Toshiyuki, Yamanaka Masayuki

DECIPHERING THE ANCIENT UNIVERSE WITH GAMMA-RAY BURSTS　1279　433-+　2010

DOI： 10.1063/1.3509337 　

ISSN： 0094-243X
Interaction-Powered Supernovae as Probes of the High-Redshift Universe Peer-reviewed

Moriya Takashi, Yoshida Naoki, Tominaga Nozomu, Blinnikov Sergei I, Maeda Keiichi, Tanaka Masaomi, Nomoto Ken'ichi

FIRST STARS AND GALAXIES: CHALLENGES FOR THE NEXT DECADE　1294　268-+　2010

DOI： 10.1063/1.3518871 　

ISSN： 0094-243X
EARLY PHASE OBSERVATIONS OF EXTREMELY LUMINOUS TYPE Ia SUPERNOVA 2009dc Peer-reviewed

Yamanaka, M, Kawabata, K. S, Kinugasa, K, Tanaka, M, Imada, A, Maeda, K, Nomoto, K, Arai, A, Chiyonobu, S, Fukazawa, Y

ASTROPHYSICAL JOURNAL LETTERS　707　(2)　L118-L122　2009/12/20

DOI： 10.1088/0004-637X/707/2/L118 　
NEBULAR PHASE OBSERVATIONS OF THE TYPE Ib SUPERNOVA 2008D/X-RAY TRANSIENT 080109: SIDE-VIEWED BIPOLAR EXPLOSION Peer-reviewed

Masaomi Tanaka, Masayuki Yamanaka, Keiichi Maeda, Koji S. Kawabata, Takashi Hattori, Takeo Minezaki, Stefano Valenti, Massimo Della Valle, D. K. Sahu, G. C. Anupama, Nozomu Tominaga, Ken'ichi Nomoto, Paolo A. Mazzali, Elena Pian

ASTROPHYSICAL JOURNAL　700　(2)　1680-1685　2009/08

DOI： 10.1088/0004-637X/700/2/1680 　

ISSN： 0004-637X
Early Spectral Evolution of the Rapidly Expanding Type Ia Supernova 2006X Peer-reviewed

Masayuki Yamanaka, Hiroyuki Naito, Kenzo Kinugasa, Naohiro Takanashi, Masaomi Tanaka, Koji S. Kawabata, Shinobu Ozaki, Shin-ya Narusawa, Kozo Sadakane

PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN　61　(4)　713-720　2009/08

DOI： 10.1093/pasj/61.4.713 　

ISSN： 0004-6264

eISSN： 2053-051X
SPECTROPOLARIMETRY OF THE UNIQUE TYPE Ib SUPERNOVA 2005bf: LARGER ASYMMETRY REVEALED BY LATER-PHASE DATA Peer-reviewed

Masaomi Tanaka, Koji S. Kawabata, Keiichi Maeda, Masanori Iye, Takashi Hattori, Elena Pian, Ken'ichi Nomoto, Paolo A. Mazzali, Nozomu Tominaga

ASTROPHYSICAL JOURNAL　699　(2)　1119-1124　2009/07

DOI： 10.1088/0004-637X/699/2/1119 　

ISSN： 0004-637X
The BROAD-LINE TYPE Ic SUPERNOVA SN 2007ru: ADDING TO THE DIVERSITY OF TYPE Ic SUPERNOVAE Peer-reviewed

D. K. Sahu, Masaomi Tanaka, G. C. Anupama, Uday K. Gurugubelli, Ken'ichi Nomoto

ASTROPHYSICAL JOURNAL　697　(1)　676-683　2009/05

DOI： 10.1088/0004-637X/697/1/676 　

ISSN： 0004-637X
EXTREMELY LUMINOUS SUPERNOVA 2006gy AT LATE PHASE: DETECTION OF OPTICAL EMISSION FROM SUPERNOVA Peer-reviewed

Koji S. Kawabata, Masaomi Tanaka, Keiichi Maeda, Takashi Hattori, Ken'ichi Nomoto, Nozomu Tominaga, Masayuki Yamanaka

ASTROPHYSICAL JOURNAL　697　(1)　747-757　2009/05

DOI： 10.1088/0004-637X/697/1/747 　

ISSN： 0004-637X
Properties of newly formed dust by sn 2006jc based on near- to mid-infrared observation with akari

I. Sakon, T. Onaka, T. Wada, Y. Ohyama, H. Kaneda, D. Ishihara, T. Tanabé, T. Minezaki, Y. Yoshii, N. Tominaga, K. Nomoto, T. Nozawa, T. Kozasa, M. Tanaka, T. Suzuki, H. Umeda, S. Ohyabu, F. Usui, H. Matsuhara, T. Nakagawa, H. Murakami

Astrophysical Journal　692　(1)　546-555　2009/02/10

DOI： 10.1088/0004-637X/692/1/546 　

ISSN： 0004-637X

eISSN： 1538-4357
TYPE Ib SUPERNOVA 2008D ASSOCIATED WITH THE LUMINOUS X-RAY TRANSIENT 080109: AN ENERGETIC EXPLOSION OF A MASSIVE HELIUM STAR Peer-reviewed

Masaomi Tanaka, Nozomu Tominaga, Ken'ichi Nomoto, S. Valenti, D. K. Sahu, T. Minezaki, Y. Yoshii, M. Yoshida, G. C. Anupama, S. Benetti, G. Chincarini, M. Della Valle, P. A. Mazzali, E. Pian

ASTROPHYSICAL JOURNAL　692　(2)　1131-1142　2009/02

DOI： 10.1088/0004-637X/692/2/1131 　

ISSN： 0004-637X

eISSN： 1538-4357
SUBARU AND KECK OBSERVATIONS OF THE PECULIAR TYPE IA SUPERNOVA 2006GZ AT LATE PHASES Peer-reviewed

Maeda, K, Kawabata, K, Li, W, Tanaka, M, Mazzali, P. A, Hattori, T, Nomoto, K, Filippenko, A

ASTROPHYSICAL JOURNAL　690　(2)　1745-1752　2009/01/10
Publisher: IOP PUBLISHING LTD
DOI： 10.1088/0004-637X/690/2/1745 　

ISSN： 0004-637X

More details Close

Recently, a few peculiar Type Ia supernovae (SNe Ia) that show exceptionally large peak luminosity have been discovered. Their luminosity requires more than 1 M(circle dot) of (56)Ni to be ejected during the explosion, suggesting that they might have originated from super-Chandrasekhar mass white dwarfs. However, the nature of these objects is not yet well understood. In particular, no data have been taken at late phases, about one year after the explosion. We report on Subaru and Keck optical spectroscopic and photometric observations of the SN Ia 2006gz, which had been classified as being one of these overluminous" SNe Ia. The late-time behavior is distinctly different from that of normal SNe Ia, reinforcing the argument that SN 2006gz belongs to a different subclass than normal SNe Ia. However, the peculiar features found at late times are not readily connected to a large amount of 56Ni; the SN is faint, and it lacks [ Fe II] and [ Fe III] emissions. If the bulk of the radioactive energy escapes the SN ejecta as visual light, as is the case in normal SNe Ia, the mass of (56)Ni does not exceed similar to 0.3 M(circle dot). We discuss several possibilities to remedy the probl
Optical photometry and spectroscopy of the Type Ibn supernova SN 2006jc until the onset of dust formation Peer-reviewed

Anupama} G.~C, Sahu} D.~K, Gurugubelli} U, K, Prabhu} T.~P, Tominaga} N, Tanaka} M, Nomoto} K

\mnras　392　(2)　894-903　2009

DOI： 10.1111/j.1365-2966.2008.14129.x 　
Optical Emission from Aspherical Core-Collapse Supernovae Peer-reviewed

Masaomi Tanaka, Keiichi Maeda, Ken'ichi Nomoto, Paolo A. Mazzali, Nozomu Tominaga, Koji S. Kawabata, Takashi Hattori

PROBING STELLAR POPULATIONS OUT TO THE DISTANT UNIVERSE　1111　413-+　2009

DOI： 10.1063/1.3141585 　

ISSN： 0094-243X
Spectral luminosity indicators in SNe Ia - The R(Si II) line strength ratio Peer-reviewed

Hachinger Stephan, Mazzali Paolo A, Tanaka Masaomi, Hillebrandt Wolfgang, Benetti Stefano

PROBING STELLAR POPULATIONS OUT TO THE DISTANT UNIVERSE　1111　573-+　2009

DOI： 10.1063/1.3141612 　

ISSN： 0094-243X
Near to Mid-Infrared Observations of Recent Supernovae with Infrared Camera (IRC) onboard AKARI Peer-reviewed

Sakon Itsuki, Onaka Takashi, Wada Takehiko, Usui Fumihiko, Kaneda Hidehiro, Ohyama Youichi, Oyabu Shinki, Ishihara Daisuke, Tanabe Toshihiko, Matsuhara Hideo, Nakagawa Takao, Murakami Hiroshi, Minezaki Takeo, Yoshii Yuzuru, Nozawa Takaya, Nomoto Ken'ichi, Tanaka Masaomi, Tominaga Nozomu, Kozasa Takashi

AKARI, A LIGHT TO ILLUMINATE THE MISTY UNIVERSE　418　181-190　2009

ISSN： 1050-3390
OPTICAL SPECTROPOLARIMETRY AND ASPHERICITY OF THE TYPE Ic SN 2007gr Peer-reviewed

Masaomi Tanaka, Koji S. Kawabata, Keiichi Maeda, Takashi Hattori, Ken'ichi Nomoto

ASTROPHYSICAL JOURNAL　689　(2)　1191-1198　2008/12

DOI： 10.1086/592325 　

ISSN： 0004-637X
Tycho Brahe's 1572 supernova as a standard type Ia as revealed by its light-echo spectrum Peer-reviewed

Oliver Krause, Masaomi Tanaka, Tomonori Usuda, Takashi Hattori, Miwa Goto, Stephan Birkmann, Ken'ichi Nomoto

NATURE　456　(7222)　617-619　2008/12

DOI： 10.1038/nature07608 　

ISSN： 0028-0836

eISSN： 1476-4687
THE PECULIAR TYPE Ib SUPERNOVA 2006jc: A WCO WOLF-RAYET STAR EXPLOSION Peer-reviewed

Tominaga, N, Limongi, M, Suzuki, T, Tanaka, M, Nomoto, K, Maeda, K, Chieffi, A, Tornambe, A, Minezaki, T, Yoshii, Y

ASTROPHYSICAL JOURNAL　687　(2)　1208-1219　2008/11/10
Publisher: UNIV CHICAGO PRESS
DOI： 10.1086/591782 　

ISSN： 0004-637X

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We present a theoretical model for Type Ib supernova (SN) 2006jc. We calculate the evolution of the progenitor star, hydrodynamics and nucleosynthesis of the SN explosion, and the SN bolometric light curve (LC). The synthetic bolometric LC is compared with the observed bolometric LC constructed by integrating the UV, optical, near-infrared (NIR), and mid-infrared (MIR) fluxes. The progenitor is assumed to be as massive as 40 M-circle dot on the zero-age main sequence. The star undergoes extensive mass loss to reduce its mass down to as small as 6.9 M-circle dot, thus becoming a WCO Wolf-Rayet star. The WCO star model has a thick carbon-rich layer, in which amorphous carbon grains can be formed. This could explain the NIR brightening and the dust feature seen in the MIR spectrum. We suggest that the progenitor of SN 2006jc is a WCO Wolf-Rayet star having undergone strong mass loss, and such massive stars are important sites of dust formation. We derive the parameters of the explosion model in order to reproduce the bolometric LC of SN 2006jc by the radioactive decays: the ejecta mass 4.9 M-circle dot, hypernova-like explosion energy 1052 ergs, and ejected Ni-56 mass 0.22 M-circle do
Early formation of dust in the ejecta of type Ib SN 2006jc and temperature and mass of the dust Peer-reviewed

Takaya Nozawa, Takashi Kozasa, Nozomu Tominaga, Itsuki Sakon, Masaomi Tanaka, Tomoharu Suzuki, Ken'ichi Nomoto, Keiichi Maeda, Hideyuki Umeda, Marco Limongi, Takashi Onaka

ASTROPHYSICAL JOURNAL　684　(2)　1343-1350　2008/09

DOI： 10.1086/589961 　

ISSN： 0004-637X
Spectral luminosity indicators in Type Ia supernovae. Understanding the R(Si II) line-strength ratio and beyond Peer-reviewed

Stephan Hachinger, Paolo A. Mazzali, Masaomi Tanaka, Wolfgang Hillebrandt, Stefano Benetti

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY　389　(3)　1087-1096　2008/09

DOI： 10.1111/j.1365-2966.2008.13645.x 　

ISSN： 0035-8711
The metamorphosis of supernova SN 2008D/XRF 080109: A link between supernovae and GRBs/hypernovae Peer-reviewed

Paolo A. Mazzali, Stefano Valenti, Massimo Della Valle, Guido Chincarini, Daniel N. Sauer, Stefano Benetti, Elena Pian, Tsvi Piran, Valerio D'Elia, Nancy Elias-Rosa, Raffaella Margutti, Francesco Pasotti, L. Angelo Antonelli, Filomena Bufano, Sergio Campana, Enrico Cappellaro, Stefano Covino, Paolo D'Avanzo, Fabrizio Fiore, Dino Fugazza, Roberto Gilmozzi, Deborah Hunter, Kate Maguire, Elisabetta Maiorano, Paola Marziani, Nicola Masetti, Felix Mirabel, Hripsime Navasardyan, Ken'ichi Nomoto, Eliana Palazzi, Andrea Pastorello, Nino Panagia, L. J. Pellizza, Re'em Sari, Stephen Smartt, Gianpiero Tagliaferri, Masaomi Tanaka, Stefan Taubenberger, Nozomu Tominaga, Carrie Trundle, Massimo Turatto

SCIENCE　321　(5893)　1185-1188　2008/08

DOI： 10.1126/science.1158088 　

ISSN： 0036-8075
The evolution of the peculiar Type Ia supernova SN 2005hk over 400 days Peer-reviewed

D. K. Sahu, Masaomi Tanaka, G. C. Anupama, Koji S. Kawabata, Keiichi Maeda, Nozomu Tominaga, Ken'ichi Nomoto, Paolo A. Mazzali, T. P. Prabhu

ASTROPHYSICAL JOURNAL　680　(1)　580-592　2008/06

DOI： 10.1086/587772 　

ISSN： 0004-637X
The outermost ejecta of Type Ia supernovae Peer-reviewed

Masaomi Tanaka, Paolo A. Mazzali, Stefano Benetti, Ken'ichi Nomoto, Nancy Elias-Rosa, Rubina Kotak, Giuliano Pignata, Vallery Stanishev, Stephan Hachinger

ASTROPHYSICAL JOURNAL　677　(1)　448-460　2008/04

DOI： 10.1086/528703 　

ISSN： 0004-637X
Asphericity in supernova explosions from late-time spectroscopy Peer-reviewed

Keiichi Maeda, Koji Kawabata, Paolo A. Mazzali, Masaomi Tanaka, Stefano Valenti, Ken'ichi Nomoto, Takashi Hattori, Jinsong Deng, Elena Pian, Stefan Taubenberger, Masanori Iye, Thomas Matheson, Alexei V. Filippenko, Kentaro Aoki, George Kosugi, Youichi Ohyama, Toshiyuki Sasaki, Tadafumi Takata

SCIENCE　319　(5867)　1220-1223　2008/02

DOI： 10.1126/science.1149437 　

ISSN： 0036-8075
The Connection between Gamma-Ray Bursts and Extremely Metal-Poor Stars as Nucleosynthetic Probes of the Early Universe Peer-reviewed

Nomoto} K, Tominaga} N, Tanaka} M, Maeda} K, Umeda} H

Massive Stars as Cosmic Engines　250　463-470　2008

DOI： 10.1017/S1743921308020838 　
Nucleosynthesis in Aspherical Explosions of Population III Stars Peer-reviewed

Nomoto} K, Tominaga} N, Tanaka} M, Maeda} K, Umeda} H

First Stars III　990　291-296　2008

DOI： 10.1063/1.2905565 　
First Stars - Type Ib Supernovae Connection Peer-reviewed

Nomoto Ken'ichi, Tanaka Masaomi, Kamiya Yasuomi, Tominaga Nozomu, Maeda Keiichi

LOW-METALLICITY STAR FORMATION: FROM THE FIRST STARS TO DWARF GALAXIES　(255)　182-+　2008

DOI： 10.1017/S1743921308024794 　

ISSN： 1743-9213
Multi-dimensional simulations of radiative transfer in aspherical core-collapse supernovae Peer-reviewed

Tanaka Masaomi, Maeda Keiichi, Mazzali Paolo A, Nomoto Ken'ichi

ORIGIN OF MATTER AND EVOLUTION OF GALAXIES　1016　249-+　2008

ISSN： 0094-243X
Multidimensional simulations for early-phase spectra of aspherical hypernovae: SN 1998bw and off-axis hypernovae Peer-reviewed

Masaomi Tanaka, Keiichi Maeda, Paolo A. Mazzali, Ken'ichi Nomoto

ASTROPHYSICAL JOURNAL　668　(1)　L19-L22　2007/10

DOI： 10.1086/522671 　

ISSN： 0004-637X
The unique type Ib Supernova 2005bf at nebular phases: A possible birth event of a strongly magnetized neutron star Peer-reviewed

Maeda, K, Tanaka, M, Nomoto, K, Tominaga, N, Kawabata, K, Mazzali, P. A, Umeda, H, Suzuki, T, Hattori, T

ASTROPHYSICAL JOURNAL　666　(2)　1069-1082　2007/09/10
Publisher: IOP PUBLISHING LTD
DOI： 10.1086/520054 　

ISSN： 0004-637X

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Late-phase nebular spectra and photometry of Type Ib Supernova ( SN) 2005bf taken by the Subaru telescope at similar to 270 and similar to 310 days since the explosion are presented. Emission lines ([O I] lambda lambda 6300, 6363; [ Ca II] lambda lambda 7291, 7324; and [Fe II] lambda 7155) show a blueshift of similar to 1500-2000 km s(-1). The [O I] doublet shows a doubly peaked profile. The line luminosities can be interpreted as coming from a blob or jet containing only similar to 0.1-0.4M(circle dot), in which similar to 0.02-0.06M(circle dot) is (56)Ni synthesized at the explosion. To explain the blueshift, the blob should either be unipolar, moving at the center-of-mass velocity nu similar to 2000-5000 km s(-1), or suffer from self-absorption within the ejecta, as seen in SN 1990I. In bothinterpretations, the low-mass blob component dominates the optical output both at the first peak (similar to 20 days) and at the late phase (similar to 300 days). The low luminosity at the late phase (the absolute R magnitude M(R) similar to -10.2 mag at similar to 270 days) sets the upper limit for the mass of 56Ni P 0: 08 M(circle dot), which is in contradiction to the value necessary to ex
The connection between gamma-ray bursts and extremely metal-poor stars: Black hole-forming supernovae with relativistic jets Peer-reviewed

Nozomu Tominaga, Keiichi Maeda, Hideyuki Umeda, Ken'Ichi Nomoto, Masaomi Tanaka, Nobuyuki Iwamoto, Tomoharu Suzuki, Paolo A. Mazzali

ASTROPHYSICAL JOURNAL　657　(2)　L77-L80　2007/03

DOI： 10.1086/513193 　

ISSN： 0004-637X
Type Ia supernovae: Progenitors and peculiarity Peer-reviewed

K. Nomoto, M. Tanaka, K. S. Kawabata, D. K. Sahu, G. C. Anupama

AIP Conference Proceedings　924　194-202　2007

DOI： 10.1063/1.2774859 　

ISSN： 0094-243X 1551-7616
Type Ia Supernovae: Progenitors and Peculiarity Peer-reviewed

K. Nomoto, M. Tanaka, K. S. Kawabata, D. K. Sahu, G. C. Anupama

MULTICOLORED LANDSCAPE OF COMPACT OBJECTS AND THEIR EXPLOSIVE ORIGINS　924　481-+　2007

ISSN： 0094-243X
The Properties of the Unique Type ib Supernova 2005bf and Implications for the Difference Between Type Ib/c Supernovae Peer-reviewed

Tanaka} Masaomi, Tominaga} Nozomu, Nomoto} Ken'ichi, Maeda} Keiichi, Mazzali} Paolo A, Deng} Jingsong

Energy Budget in the High Energy Universe　369-372　2007

DOI： 10.1142/9789812708342_0047 　
SN 2006aj Associated with XRF 060218 at Late Phases: Nucleosynthesis Signature of a Neutron Star-driven Explosion Peer-reviewed

Maeda} K, Kawabata} K, Tanaka} M, Nomoto} K, Tominaga} N, Hattori} T, Minezaki} T, Kuroda} T, Suzuki} T, Deng} J, Mazzali} P.~A, Pian} E

\apjl　658　(1)　L5-L8　2007

DOI： 10.1086/513564 　
Nucleosynthesis in Core-Collapse Supernovae and GRB-Metal-Poor Star Connection Peer-reviewed

Nomoto} K, Tominaga} N, Tanaka} M, Maeda} K, Umeda} H

Supernova 1987A: 20 Years After: Supernovae and Gamma-Ray Bursters　937　412-426　2007

DOI： 10.1063/1.3682938 　
Hypernovae and their Gamma-Ray Bursts Connection Peer-reviewed

Nomoto} Ken'ichi, Tanaka} Masaomi, Tominaga} Nozomu, Maeda} Keiichi, Mazzali} Paolo A

arXiv e-prints　arXiv:0707.2219　2007
Diversity of the GRB-Supernova Connection: X-Ray Flashes and Dark Hypernovae Peer-reviewed

Nomoto} K, Tominaga} N, Tanaka} M, Maeda} K

The Multicolored Landscape of Compact Objects and Their Explosive Origins　924　108-119　2007

DOI： 10.1063/1.2774847 　
Diversity of the GRB-Supernova connection: X-ray-flash SNe and non-SN GRBs Peer-reviewed

Ken'ichi Nomoto, Nozomu Tominaga, Masaomi Tanaka, Keiichi Maeda, Tomoharu Suzuki

PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT　(169)　7-11　2007

ISSN： 0375-9687
The Asymmetric Explosion of Type Ia Supernovae as Seen from Near-Infrared Observations Peer-reviewed

Motohara, Kentaro, Maeda, Keiichi, Gerardy, Christopher L., Nomoto, Ken'ichi, Tanaka, Masaomi, Tominaga, Nozomu, Ohkubo, Takuya, Mazzali, Paolo A., Fesen, Robert A., Hoflich, Peter, Wheeler, J. Craig

The Astrophysical Journal　652　(2)　L101-L104　2006/12/01

DOI： 10.1086/509919 　

ISSN： 1538-4357
The asymmetric explosion of type Ia supernovae as seen from near-infrared observations Peer-reviewed

Kentaro Motohara, Keiichi Maeda, Christopher L. Gerardy, Ken'ichi Nomoto, Masaomi Tanaka, Nozomu Tominaga, Takuya Ohkubo, Paolo A. Mazzali, Robert A. Fesen, Peter Hoflich, J. Craig Wheeler

ASTROPHYSICAL JOURNAL　652　(2)　L101-L104　2006/12

DOI： 10.1086/509919 　

ISSN： 0004-637X
A neutron-star-driven X-ray flash associated with supernova SN 2006aj Peer-reviewed

Paolo A. Mazzali, Jinsong Deng, Ken'ichi Nomoto, Daniel N. Sauer, Elena Pian, Nozomu Tominaga, Masaomi Tanaka, Keiichi Maeda, Alexei V. Filippenko

NATURE　442　(7106)　1018-1020　2006/08

DOI： 10.1038/nature05081 　

ISSN： 0028-0836
Three-dimensional models for high-velocity features in Type Ia supernovae Peer-reviewed

Masaomi Tanaka, Paolo A. Mazzali, Keiichi Maeda, Ken'ichi Nomoto

ASTROPHYSICAL JOURNAL　645　(1)　470-479　2006/07

DOI： 10.1086/504102 　

ISSN： 0004-637X
Aspherical ejecta of Type Ia supernovae inferred from high velocity features Peer-reviewed

M. Tanaka, P. A. Mazzali, K. Maeda, K. Nomoto

ORIGIN OF MATTER AND EVOLUTION OF GALAXIES　847　485-+　2006

ISSN： 0094-243X
Diversity of the supernova--gamma-ray burst connection Peer-reviewed

Nomoto} K, Tominaga} N, Tanaka} M, Maeda} K, Suzuki} T, Deng} J.~S, Mazzali} P.~A

Nuovo Cimento B Serie　121　(10)　1207-1222　2006

DOI： 10.1393/ncb/i2007-10245-6 　
The unique type Ib supernova 2005bf: A WN star explosion model for peculiar light curves and spectra Peer-reviewed

Tominaga, N, Tanaka, M, Nomoto, K, Mazzali, PA, Deng, J, Maeda, K, Umeda, H, Modjaz, M, Hicken, M, Challis, P

ASTROPHYSICAL JOURNAL　633　(2)　L97-L100　2005/11/10
Publisher: UNIV CHICAGO PRESS
DOI： 10.1086/498570 　

ISSN： 0004-637X

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Observations and modeling for the light curve (LC) and spectra of supernova (SN) 2005bf are reported. This SN showed unique features: the LC had two maxima, and declined rapidly after the second maximum, while the spectra showed strengthening He lines whose velocity increased with time. The double-peaked LC can be reproduced by a double-peaked Ni-56 distribution, with most Ni-56 at low velocity and a small amount at high velocity. The rapid postmaximum decline requires a large fraction of the gamma-rays to escape from the Ni-56-dominated region, possibly because of low-density holes." The presence of Balmer lines in the spectrum suggests that the He layer of the progenitor was substantially intact. Increasing gamma-ray deposition in the He layer due to enhanced gamma-ray escape from the Ni-56-dominated region may explain both the delayed strengthening and the increasing velocity of the He lines. The SN has massive ejecta (similar to 6-7 M.), normal kinetic energy [similar to(1.0-1.5) x 10(51) ergs], a high peak bolometric luminosity (similar to 5 x 10(42) ergs s(-1)) for an epoch as late as similar to 40 days, and a large Ni-56 mass (similar to 0.32 M.). These properties and t
The Peculiar Type Ib Supernova SN 2005bf: Explosion of a Massive He Star with a Thin Hydrogen Envelope? Peer-reviewed

Anupama} G.~C, Sahu} D.~K, Deng} J, Nomoto} K, Tominaga} N, Tanaka} M, Mazzali} P.~A, Prabhu} T

\apjl　631　(2)　L125-L128　2005

DOI： 10.1086/497336

Show all ︎Show first 5

Misc. 42

高速CMOSカメラTomo-e GozenによるFast Radio Burst可視光放射の探査

新納悠, 土居守, 酒向重行, 大澤亮, 有馬宣明, 小林尚人, 高橋英則, 近藤荘平, 森由貴, 青木勉, 冨永望, JIANG Ji-an, 春日敏測, 田中雅臣, LI Di, NIU Chen-Hui, TSAI Chao-Wei, 有松亘, 奥村真一郎

日本天文学会年会講演予稿集　2022　2022

ISSN： 1347-0639
すばる望遠鏡広帯域分光装置NINJA:装置概要

東谷千比呂, 吉田道利, 守屋尭, 本原顕太郎, 尾崎忍夫, 柳澤顕史, 大野良人, 美濃和陽典, 早野裕, 小山佑世, 冨永望, 大内正己, 田中賢幸, 田中雅臣, 秋山正幸, 長尾透, 松岡良樹, 櫛引洸佑, 穂満星冴

日本天文学会年会講演予稿集　2022　2022

ISSN： 1347-0639
すばる望遠鏡広帯域分光装置NINJA:科学目標

守屋尭, 吉田道利, 東谷千比呂, 本原顕太郎, 尾崎忍夫, 柳澤顕史, 大野良人, 小山佑世, 冨永望, 大内正己, 美濃和陽典, 早野裕, 田中賢幸, 田中雅臣, 秋山正幸, 長尾透, 松岡良樹, 櫛引洸佑, 穂満星冴

日本天文学会年会講演予稿集　2022　2022

ISSN： 1347-0639
機械学習を使用したすばるHyper Suprime-Cam超新星のタイプ分類

高橋一郎, 田中雅臣, 鈴木尚孝, 安田直樹, 吉田直紀, 木村昭悟, 上田修功, 冨永望

日本天文学会年会講演予稿集　2021　2021

ISSN： 1347-0639
木曽Tomo-e Gozenの広域動画サーベイのデータ公開に向けた開発

酒向重行, 大澤亮, 諸隈智貴, 新納悠, 瀧田怜, 土居守, 茂山俊和, 小林尚人, 小西真広, 高橋英則, 近藤荘平, 森由貴, 青木勉, 紅山仁, 渡部潤一, 冨永望, 田中雅臣, 奥村真一郎, 池田思朗

日本天文学会年会講演予稿集　2021　2021

ISSN： 1347-0639
重力波事象S200224caにおけるすばる/HSCでの追観測

大神隆幸, 冨永望, 吉田道利, 柳澤顕史, 田中雅臣, 笹田真人, 諸隈智貴, 新納悠, 鹿内みのり, 内海洋輔, 伊藤亮介, 森鼻久美子, 村田勝寛, 松林和也, 宝田拓也, 小野里宏樹, 関口雄一郎

日本天文学会年会講演予稿集　2021　2021

ISSN： 1347-0639
重力波観測ランO3におけるすばる/HSCでの観測

大神隆幸, 冨永望, 吉田道利, 柳澤顕史, 田中雅臣, 笹田真人, 諸隈智貴, 新納悠, 鹿内みのり, 内海洋輔, 伊藤亮介, 森鼻久美子, 亀井悠平, 村田勝寛, 松林和也, 宝田拓也, 小野里宏樹, 関口雄一郎

日本天文学会年会講演予稿集　2020　2020

ISSN： 1347-0639
重力波観測ランO3におけるJ-GEMによる電磁波対応天体探査

笹田真人, 吉田道利, 田中雅臣, 冨永望, 諸隈智貴, 内海洋輔, 伊藤亮介, 森鼻久美子, 亀井悠平, 村田勝寛, 柳澤顕史, 松林和也, 宝田拓也, 小野里宏樹, 関口雄一郎

日本天文学会年会講演予稿集　2020　2020

ISSN： 1347-0639
重力波観測ランO3におけるJ-GEMのすばるでの観測状況とTMTとの連携

大神隆幸, 冨永望, 吉田道利, 柳澤顕史, 田中雅臣, 笹田真人, 諸隈智貴, 新納悠, 鹿内みのり, 内海洋輔, 伊藤亮介, 森鼻久美子, 亀井悠平, 村田勝寛, 松林和也, 宝田拓也, 小野里宏樹, 関口雄一郎

日本天文学会年会講演予稿集　2019　2019

ISSN： 1347-0639
速い速度進化を示すIa型超新星SN 2019einの爆発初期からの観測

川端美穂, 山中雅之, 前田啓一, 磯貝桂介, 田口健太, 中岡竜也, 木村浩輝, 高木健吾, 川端弘治, 長尾崇史, 高木聖子, 田中雅臣, 諸隈智貴, JIANG Jian, 村田勝寛, 守屋尭, 花山秀和, 堀内貴史, 前原裕之, 関口和寛, 森鼻久美子, 野上大作, 冨永望, 高橋隼, 小野里宏樹, 加藤則行, 斎藤智樹

日本天文学会年会講演予稿集　2019　2019

ISSN： 1347-0639
重力波観測ランO3におけるJ-GEMの重力波フォローアップ

笹田真人, 吉田道利, 田中雅臣, 冨永望, 諸隈智貴, 内海洋輔, 伊藤亮介, 森鼻久美子, 亀井悠平, 村田勝寛, 柳澤顕史, 松林和也, 宝田拓也, 小野里宏樹, 関口雄一郎

日本天文学会年会講演予稿集　2019　2019

ISSN： 1347-0639
紫外線広視野サーベイのためのキューブサットの開発 II

谷津陽一, 間宮英夫, 小澤俊貴, 河合誠之, 新谷勇介, 菊谷侑平, 松永三郎, 冨永望, 田中雅臣, 諸隈智貴, NIKZAD Shouleh, NIKZAD Shouleh, BILGI Pavaman, KULKARNI Shrinivas, 武山芸英, 江野口章人

日本天文学会年会講演予稿集　2019　2019

ISSN： 1347-0639
木曽超広視野高速CMOSカメラTomo‐e Gozen FM筐体の開発 II

高橋英則, 酒向重行, 大澤亮, 一木真, 小島悠人, 土居守, 小林尚人, 本原顕太郎, 宮田隆志, 諸隈智貴, 小西真広, 有馬宣明, 青木勉, 征矢野隆夫, 樽沢賢一, 猿楽祐樹, 森由貴, 中田好一, 戸谷友則, 松永典之, 茂山俊和, 臼井文彦, 渡部潤一, 山下卓也, 春日敏測, 有松亘, 猪岡皓太, 冨永望, 田中雅臣, 板由房, 小久保充, 満田和真, 前原裕之, 奥村真一郎, 浦川聖太郎, 池田思朗, 森井幹雄, 佐藤幹哉

日本天文学会年会講演予稿集　2018　202　2018/08/20

ISSN： 1347-0639
GW170817:J‐GEMによる可視近赤外線追跡観測

内海洋輔, 田中雅臣, 吉田道利, 黒田大介, 冨永望, 永山貴宏, 朝倉悠一朗, 阿部文雄, 川端弘治, 伊藤亮介, 伊藤洋一, 大澤亮, 諸隈智貴

日本天文学会年会講演予稿集　2018　243　2018/02/20

ISSN： 1347-0639
木曽超広視野高速CMOSカメラTomo‐e Gozen試験機による微光流星観測

大澤亮, 酒向重行, 猿楽祐樹, 臼井文彦, 大坪貴文, 佐藤幹哉, 藤原康徳, 有松亘, 春日敏測, 渡部潤一, 土居守, 小林尚人, 高橋英則, 本原顕太郎, 宮田隆志, 諸隈智貴, 小西真広, 青木勉, 征矢野隆夫, 樽澤賢一, 森由貴, 中田好一, 満田和真, 一木真, 有馬宣明, 小島悠人, 戸谷友則, 松永典之, 茂山俊和, 冨永望, 板由房, 小久保充, 山下卓也, 田中雅臣, 前原裕之, 猪岡皓太, 池田思朗, 森井幹雄, 浦川聖太郎, 奥村真一郎

日本天文学会年会講演予稿集　2017　59　2017/08/20

ISSN： 1347-0639
すばるHSCデータを使用した機械学習による超新星タイプ分類

高橋一郎, 木村昭悟, 上田修功, 安田直樹, 鈴木尚孝, 田中雅臣, 守屋尭, 冨永望, 諸隈智貴, 吉田直紀, 吉田直紀

日本天文学会年会講演予稿集　2017　2017

ISSN： 1347-0639
J‐GEMによるLIGO重力波源に対する電磁波フォローアップ観測

諸隈智貴, 田中雅臣, 朝倉悠一朗, 阿部文雄, TRISTRAM Paul, 内海洋輔, 土居守, 本原顕太郎, 田村陽一, 酒向重行, 大澤亮, 藤沢健太, 伊藤亮介, 植村誠, 川端弘治, 吉田道利, 伊藤洋一, 河合誠之, 斉藤嘉彦, 谷津陽一, 黒田大介, 柳澤顕史, 松林和也, 太田耕司, 村田勝寛, 永山貴宏, 冨永望

日本天文学会年会講演予稿集　2016　62　2016/08/20

ISSN： 1347-0639
Radioactive decay products in neutron star merger ejecta: heating efficiency and gamma-ray emission

K. Hotokezaka, S. Wanajo, M. Tanaka, A. Bamba, Y. Terada, T. Piran

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY　459　(1)　35-43　2016/06

DOI： 10.1093/mnras/stw404 　

ISSN： 0035-8711

eISSN： 1365-2966
木曽超広視野高速CMOSカメラTomo‐eのイメージセンサ評価試験

菊池勇輝, 酒向重行, 小林尚人, 土居守, 本原顕太郎, 宮田隆志, 諸隈智貴, 高橋英則, 大澤亮, 青木勉, 征矢野隆夫, 樽沢賢一, 三戸洋之, 中田好一, 松永典之, 臼井文彦, 猿楽祐樹, 谷口由貴, 田中雅臣, 渡部潤一, 前原裕之, 有松亘, 冨永望, 板由房, 小野里宏樹, 花上拓海, 岩崎仁美, 浦川聖太郎, 佐藤幹哉, 河北秀世, 近藤荘平, 谷川衝

日本天文学会年会講演予稿集　2015　229　2015/08/20

ISSN： 1347-0639
光赤外線大学間連携によるスーパーチャンドラセカール超新星候補SN2012dnのToO観測:赤外超過とダスト放射

山中雅之, 山中雅之, 前田啓一, 川端弘治, 田中雅臣, 冨永望, 高木勝俊, 川端美穂, 上野一誠, 伊藤亮介, 秋田谷洋, 森谷友由希, 諸隈智貴, 永山貴宏, 磯貝瑞希, 花山秀和, 黒田大介, 浮田信治, 前原裕之, 関口和寛, 高橋隼, 高木悠平, 新井彰, 宮ノ下亮, 斉藤嘉彦, 渡辺誠, 野口亮, 増本一成, 松本桂, 小野里佳子, 野上大作, 大朝由美子, 村田勝寛, 奥村真一郎

日本天文学会年会講演予稿集　2015　91　2015/08/20

ISSN： 1347-0639
木曽超広視野高速CMOSカメラTomo‐eによるTNO掩蔽現象の捜索

有松亘, 渡部潤一, 田中雅臣, 前原裕之, 臼井文彦, 猿楽祐樹, 大坪貴文, 大澤亮, 酒向重行, 小林尚人, 土居守, 本原顕太郎, 宮田隆志, 諸隈智貴, 高橋英則, 青木勉, 征矢野隆夫, 樽沢賢一, 三戸洋之, 中田好一, 菊池勇輝, 谷口由貴, 松永典之, 和田武彦, 冨永望, 板由房, 小野里宏樹, 花上拓海, 岩崎仁美, 浦川聖太郎, 佐藤幹哉, 河北秀世, 近藤荘平, 谷川衝

日本天文学会年会講演予稿集　2015　230　2015/08/20

ISSN： 1347-0639
超広視野高速CMOSカメラTomo‐eの観測戦略

酒向重行, 小林尚人, 土居守, 本原顕太郎, 宮田隆志, 諸隈智貴, 高橋英則, 大澤亮, 青木勉, 征矢野隆夫, 樽沢賢一, 三戸洋之, 中田好一, 藤堂颯哉, 菊池勇輝, 松永典之, 臼井文彦, 有松亘, 田中雅臣, 前原裕之, 冨永望, 板由房, 小野里宏樹, 花上拓海, 岩崎仁美, 猿楽祐樹, 浦川聖太郎, 佐藤幹哉, 河北秀世, 近藤荘平, 谷川衝

日本天文学会年会講演予稿集　2015　246　2015/02/20

ISSN： 1347-0639
超広視野高速CMOSカメラTomo‐eのバックエンド解析システムの開発

大澤亮, 酒向重行, 小林尚人, 土居守, 本原顕太郎, 宮田隆志, 諸隈智貴, 高橋英則, 青木勉, 征矢野隆夫, 樽沢賢一, 三戸洋之, 中田好一, 藤堂颯哉, 菊池勇輝, 松永典之, 臼井文彦, 有松亘, 田中雅臣, 渡部潤一, 前原裕之, 冨永望, 板由房, 小野里宏樹, 花上拓海, 岩崎仁美, 猿楽祐樹, 浦川聖太郎, 佐藤幹哉, 河北秀世, 近藤荘平, 谷川衝

日本天文学会年会講演予稿集　2015　247　2015/02/20

ISSN： 1347-0639
超広視野高速CMOSカメラTomo‐eの読み出しシステムの開発

菊池勇輝, 酒向重行, 小林尚人, 土居守, 本原顕太郎, 宮田隆志, 諸隈智貴, 高橋英則, 大澤亮, 青木勉, 征矢野隆夫, 樽沢賢一, 三戸洋之, 中田好一, 藤堂颯哉, 松永典之, 臼井文彦, 有松亘, 田中雅臣, 渡部潤一, 前原裕之, 冨永望, 板由房, 小野里宏樹, 花上拓海, 岩崎仁美, 猿楽祐樹, 浦川聖太郎, 佐藤幹哉, 河北秀世, 近藤荘平, 谷川衝

日本天文学会年会講演予稿集　2015　247　2015/02/20

ISSN： 1347-0639
KWFC銀河面変光天体探査(KISOGP)―III

松永典之, 前原裕之, 坂本強, 浮田信治, 三戸洋之, 小林尚人, 泉奈都子, 山本遼, 福江慧, 青木勉, 征矢野隆夫, 樽澤賢一, 酒向重行, 諸隈智貴, 土居守, 田中雅臣, 岩田生, 柳澤顕史, 板由房, 小野里宏樹, 岩崎仁美, 花上拓海, 山下智志, 新井彰

日本天文学会年会講演予稿集　2015　138　2015/02/20

ISSN： 1347-0639
KWFC銀河面変光天体探査(KISOGP)-IV

松永典之, 岩崎仁美, 前原裕之, 浮田信治, 坂本強, 三戸洋之, 小林尚人, 泉奈都子, 山本遼, 福江慧, 青木勉, 征矢野隆夫, 樽澤賢一, 猿楽祐樹, 酒向重行, 諸隈智貴, 土居守, 中田好一, 田中雅臣, 岩田生, 柳澤顕史, 板由房, 小野里宏樹, 花上拓海, 山下智志, 新井彰

日本天文学会年会講演予稿集　2015　2015

ISSN： 1347-0639
光赤外線大学間連携における超新星爆発のToO観測状況報告 II

山中雅之, 川端弘治, 高木勝俊, 秋田谷洋, 前田啓一, 野上大作, 田中雅臣, 関口和寛, 黒田大介, 花山秀和, 磯貝瑞希, 永山貴宏, 斉藤嘉彦, 新井彰, 高橋隼, 渡辺誠, 諸隈智貴, 前原裕之, 大朝由美子, 村田勝寛, 奥村真一郎, 河北秀世

日本天文学会年会講演予稿集　2014　67　2014/08/20

ISSN： 1347-0639
近傍銀河M82に現れた赤化の大きなIa型超新星SN 2014Jの偏光特性

川端弘治, 秋田谷洋, 山中雅之, 伊藤亮介, 森谷友由希, 宇井崇紘, 川端美穂, 森健彰, 高木勝俊, 上野一誠, 前田啓一, 野上大作, 野本憲一, 鈴木尚孝, 田中雅臣, 千代延真吾, 原尾達也, 松井理紗子, 宮本久嗣, 永江修, 大橋佑馬, 大杉節, 小松智之, 先本清志, 佐藤久之, 田中祐行, 浦野剛志, 吉田道利, 胡田奈那, 深沢泰司, 神田優花, 高田紘司, 中岡竜也, 植村誠, 笹田真人, 中屋秀彦, 山下卓也, 福井暁彦, 泉浦秀行, 黒田大介

日本天文学会年会講演予稿集　2014　113　2014/08/20

ISSN： 1347-0639
KWFC銀河面変光天体探査(KISOGP)のデータを用いた突発天体サーベイ

前原裕之, 松永典之, 三戸洋之, 小林尚人, 泉奈都子, 山本遼, 青木勉, 征矢野隆夫, 樽澤賢一, 酒向重行, 諸隈智貴, 土居守, 坂本強, 浮田信治, 田中雅臣, 板由房, 小野里宏樹, 岩崎仁美, 花上拓海, 山下智志

日本天文学会年会講演予稿集　2014　264　2014/08/20

ISSN： 1347-0639
KWFC銀河面変光天体探査(KISOGP)―II

松永典之, 前原裕之, 三戸洋之, 小林尚人, 泉奈都子, 山本遼, 青木勉, 征矢野隆夫, 樽澤賢一, 酒向重行, 諸隈智貴, 土居守, 坂本強, 浮田信治, 田中雅臣, 岩田生, 板由房, 小野里宏樹, 岩崎仁美, 花上拓海, 山下智志, 新井彰

日本天文学会年会講演予稿集　2014　203　2014/02/20

ISSN： 1347-0639
木曽広視野高速カメラTomoeの開発

酒向重行, 土居守, 本原顕太郎, 宮田隆志, 小林尚人, 諸隈智貴, 高橋英則, 藤堂颯哉, 菊池勇輝, 青木勉, 征矢野隆夫, 樽沢賢一, 前原裕之, 三戸洋之, 中田好一, 臼井文彦, 松永典之, 田中雅臣, 渡部潤一, 冨永望, 猿楽祐樹, 有松亘, 板由房, 小野里宏樹, 花上拓海, 岩崎仁美

天文学に関する技術シンポジウム集録　34th　9-10　2014
KWFC銀河面変光天体探査(KISOGP)

松永典之, 前原裕之, 三戸洋之, 小林尚人, 泉奈都子, 青木勉, 征矢野隆夫, 樽澤賢一, 酒向重行, 諸隈智貴, 土居守, 坂本強, 浮田信治, 田中雅臣, 板由房, 小野里宏樹, 山下智志

日本天文学会年会講演予稿集　2013　124　2013/08/20

ISSN： 1347-0639
光赤外線大学間連携によるsuper‐Chandrasekhar候補SN2012dnの観測

山中雅之, 川端弘治, 上野一誠, 高木勝俊, 伊藤亮介, 森谷友由希, 秋田谷洋, 永山貴宏, 磯貝瑞希, 花山秀和, 高木悠平, 新井彰, 宮ノ下亮, 黒田大介, 浮田信治, 斉藤嘉彦, 渡辺誠, 増本一成, 松本桂, 綾仁一哉, 前田啓一, 野本憲一, 田中雅臣

日本天文学会年会講演予稿集　2013　110　2013/02/20

ISSN： 1347-0639
光赤外線大学間連携による特異なIa型超新星SN 2012Zの初期観測

山中雅之, 川端弘治, 伊藤亮介, 宇井崇紘, 秋田谷洋, 永山貴宏, 黒田大介, 柳沢顕史, 谷津陽一, 斉藤嘉彦, 新井彰, 磯貝瑞希, 高橋隼, 宮ノ下亮, 花山秀和, 渡辺誠, 田中雅臣, 前田啓一, 野本憲一

日本天文学会年会講演予稿集　2012　324　2012/08/20

ISSN： 1347-0639
光赤外線大学間連携による特異なIa型超新星SN 2012Zの初期観測 II

山中雅之, 川端弘治, 伊藤亮介, 宇井崇紘, 秋田谷洋, 上野一誠, 高木勝俊, 永山貴宏, 黒田大介, 柳沢顕史, 谷津陽一, 斉藤嘉彦, 新井彰, 高橋隼, 磯貝瑞希, 宮ノ下亮, 花山秀和, 渡辺誠, 田中雅臣, 前田啓一, 野本憲一

日本天文学会年会講演予稿集　2012　102　2012/08/20

ISSN： 1347-0639
大学間連携観測ネットワークによる近傍銀河M101に出現したIa型超新星SN2011fe/PTF11klyの爆発直後からの連続可視近赤外線観測

山中雅之, 川端弘治, 伊藤亮介, 宇井崇紘, 奥嶋貴子, 山崎翔子, 先本清志, 笹田真人, 原尾達也, 高木勝俊, 秋田谷洋, 吉田道利, 新井彰, 磯貝瑞希, 高橋隼, 時政典孝, 宮ノ下亮, 中井千尋, 面高俊宏, 橋本修, 高橋英則, 黒田大介, 泉浦秀行, 柳沢顕史, 今田明, 渡辺誠, 濱本昂, 尾崎彰士, 中尾光, 花山秀和, 宮地竹史, 谷津陽一, 斉藤嘉彦, 河合誠之, 松永典之, 諸隈智貴, 野上大作, 田中雅臣, 前田啓一, 野本憲一

日本天文学会年会講演予稿集　2012　125　2012/02/20

ISSN： 1347-0639
Ia型超新星SN 2011byの大学間連携キャンペーン可視近赤外観測

山中雅之, 秋田谷洋, 川端弘治, 植村誠, 吉田道利, 伊藤亮介, 宇井崇紘, 渡辺誠, 河合誠之, 谷津陽一, 関口和寛, 三戸洋之, 松永典之, 家中信幸, 青木勉, 新井彰, 磯貝瑞希, 梶川智代, 長島雅佳, 今田明, 黒田大介, 柳澤顕史, 泉浦秀行, 面高俊宏, 宮ノ下亮, 花山秀和, 宮地竹史, 田中雅臣, 前田啓一, 野本憲一

日本天文学会年会講演予稿集　2011　85　2011/08/20

ISSN： 1347-0639
Late-phase observations of a super-chandrasekhar SN Ia Peer-reviewed

M. Yamanaka, K.S. Kawabata, K. Maeda, M. Tanaka, M. Yoshida, T. Hattori, K. Nomoto, T. Komatsu, T. Okushima

Proceedings of the International Astronomical Union　7　(S281)　319-321　2011

DOI： 10.1017/S1743921312015281 　
Successful Spectroscopic Observations of Historical Supernovae

USUDA Tomonori, TANAKA Masaomi

Butsuri　65　(4)　226-231　2010/04/05
Publisher: The Physical Society of Japan (JPS)
ISSN： 0029-0181

More details Close

It is thought that one supernova (SN) takes place in one galaxy per 〜50-100 years. However, there is no convincing historical record of SNe in our Galaxy in these 〜400 years. In this period, the telescope and the spectrograph were invented, and many extragalactic SNe have been observed. We have started a project to find the "light echo" from the two historical Galactic SNe, Tycho's SN (recorded in 1572) and Cassiopeia A (recorded possibly in 1680). By performing spectroscopy of the echo with Subaru telescope, we uncover the mystery of these famous SNe.
Probing Explosion Geometry of Supernovae

TANAKA Masaomi

The astronomical herald　103　(1)　53-60　2009/12/20
Publisher: 日本天文学会
ISSN： 0374-2466
極めて明るいIa型超新星SN2009dcの可視近赤外観測

山中雅之, 川端弘治, 衣笠健三, 田中雅臣, 今田明, 前田啓一, 野本憲一, 笹田真人, 伊藤亮介, 池尻祐輝, 新井彰, 永江修, 千代延真吾, 田中祐行, 小松智之, 本田敏志, 橋本修, 高橋英則, 田口光, 吉田道利, 柳澤顕史, 黒田大介, 河合誠之, 坂井伸行, 面高俊宏, 中屋秀彦, 鎌田有紀子

日本天文学会年会講演予稿集　2009　86　2009/08/20

ISSN： 1347-0639
「あかり」衛星の捉えたType Ib超新星2006jcによるダスト形成

左近樹, 尾中敬, 和田武彦, 大山陽一, 金田英宏, 冨永望, 田中雅臣, 野本憲一, 野本憲一, 峰崎岳夫, 吉井譲, 野沢貴也, 小笹隆司, 石原大助, 梅田秀之, 鈴木知治, 田邉俊彦, 臼井文彦, 大藪進喜, 中川貴雄, 松原英雄, 村上浩

日本天文学会年会講演予稿集　2008　2008

ISSN： 1347-0639

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Books and Other Publications 2

マルチメッセンジャー天文学が捉えた新しい宇宙の姿宇宙の物質の起源に迫る (ブルーバックス)

田中雅臣

講談社　2021/12/16

ISBN: 4065261341
星が「死ぬ」とはどういうことか (BERET SCIENCE)

田中雅臣

ベレ出版　2015/07/23

ISBN: 4860644425

Research Projects 17

Elucidating Nucleosynthesis of Neutron Star Mergers using a Telescope at the World Highest Observatory

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (S)

2023/04/12 - 2028/03/31
光赤外線・電波が届ける宇宙の物質生成の証

田中雅臣, 冨永望, 新沼浩太郎, 谷津陽一, 太田耕司, 川端弘治, 松林和也, 諸隈智貴

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 学術変革領域研究(A)

Institution: 東北大学

2023/04/01 - 2028/03/31
The creation of multimessenger astrophysics

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Transformative Research Areas (A)

Institution: Chiba University

2023/04/01 - 2028/03/31
原子物理と宇宙物理の連携で迫る多様な中性子星合体の元素合成

田中雅臣, 田沼肇, 中村信行, 加藤太治, 大石鉄太郎

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 基盤研究(A)

Institution: 東北大学

2023/04/01 - 2027/03/31
Study of r-process nucleosynthesis of gravitational wave sources by means of high sensitivity wide-band near infrared spectroscopy

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (S)

Institution: National Astronomical Observatory of Japan

2021/07/05 - 2026/03/31
Time-domain astronomy in the distant Universe with Subaru/Hyper Suprime-Cam

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (A)

Institution: National Astronomical Observatory of Japan

2020/04/01 - 2024/03/31
Computing electromagnetic and gravitational-wave signals from neutron star mergers

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (A)

Institution: Kyoto University

2020/04/01 - 2024/03/31
新しい精密重元素原子データで読み解く中性子星合体の元素合成

田中雅臣, 田沼肇, 中村信行, 加藤太治

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 基盤研究(A)

Institution: 東北大学

2019/04/01 - 2023/03/31

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中性子星合体からの電磁波放射（キロノバ）の性質、特に合体から一日以内の初期放射の特性を理解するために、高階電離の重元素の網羅的な原子構造計算を行った。2017年に観測された中性子星合体イベントGW170817/AT2017gfoでは、最初の数日の放射では比較的軽い中性子捕獲元素（rプロセス元素）の存在が示唆されているため、rプロセス元素の中で比較的軽いバリウム（原子番号56）までを対象にし、四階電離から十階電離までのイオンの原子構造を網羅的に計算した。この結果を用いて、中性子星合体の放出物質におけるrプロセス元素の不透明度を計算し、合体から一日以内の物理状況に適用できる重元素の不透明度の現実的なデータを初めて提供した。さらに、この新しいデータを用いてキロノバの輻射輸送シミュレーションを行い、GW170817/AT2017gfoの合体から12時間後程度の観測データが、rプロセス元素の放射性崩壊によるキロノバで説明できることを明らかにした。また、2019年度に行った理論計算による網羅的な原子データの精度を検証するため、ランタノイド元素の一つであるエルビウム（原子番号68）の分光実験に着手している。今年度は、レーザー誘起ブレークダウン分光実験装置のために新たな低分散分光器を導入し、幅広い波長領域のスペクトルを効率的に取得することが可能となった。この新しい分光器を用いて既にエルビウムの発光スペクトルを取得できており、ラインの同定と遷移確率の導出を進めている。
Study of nucleosynthesis in neutron star merger with optical-infrared follow-up observations of gravitational wave sources

Yoshida Michitoshi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)

Institution: National Astronomical Observatory of Japan

2017/06/30 - 2022/03/31

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We developed a suite of instruments for gravitational wave (GW) follow-up observations and established a GW follow-up observation network using domestic and foreign telescopes to conduct optical and infrared follow-up observations of GW sources. As a result, we succeeded in detecting the electromagnetic counterpart AT2017gfo to the neutron star merger GW170817 through follow-up observations using the telescope network including Subaru Telescope. The optical and near-infrared luminosity curves of AT2017gfo provide evidence that heavy elements are synthesized in the neutron star merger by a rapid neutron capture reaction. Numerical relativity simulations of neutron star mergers as well as radiative transfer calculations based on unprecedentedly detailed atomic data have revealed the relationship between the physical processes of neutron star mergers, electromagnetic radiation, and the composition of synthesized heavy elements.
Gravitational waves and electromagnetic signals from the merger of neutron star binaries

Shibata Masaru

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (A)

Institution: Kyoto University

2016/04/01 - 2020/03/31

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By radiation/magnetohdyrodynamics/viscoushydrodynamics numerical simulations in general relativity, merger process of neutron star binaries, which are among the most promising sources of gravitational waves for currently operating gravitational-wave detectors, are explored to clarify the merger process, gravitational waves emitted, and mass ejection processes. Furthermore, using the results of the mass ejection, nucleosynthesis calculation is performed to derive the abundance pattern of the elements in the ejecta and also the lightcurves of kilonovae, which shine by the radioactive decay energy from the synthesized heavy elements. Particularly emphasized in our research achievement is that our theoretical calculations can reproduce the observational results of electromagnetic counterparts of GW170817.
Exploring the Frontier of Time-Domain Astronomy with Large Survey Observations

TANAKA Masaomi, FURUSAWA Hisanori

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (A)

2015/04/01 - 2019/03/31

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We have performed time-domain transient surveys using a wide-field camera Hyper Suprime-Cam installed to the Subaru Telescope. Using a dedicated real-time transient finding system that we developed, we have discovered transient objects with timescales shorter than 1 day. By comparing the observed properties and results of theoretical calculations, we show that more than 1% of massive stars in the Universe experience intensive mass loss just before the explosion.
重力波源の可視光対応天体探査

田中雅臣

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 新学術領域研究(研究領域提案型)

Institution: 国立天文台

2015/04/01 - 2017/03/31

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当初の計画通り、東京大学木曽観測所の1.05mシュミット望遠鏡と広視野カメラKWFC (Kiso Wide Field Camera)を用いて、Advanced LIGOからの重力波アラートを受けた突発天体サーベイ観測を行った。平成２７年９月より、Advanced LIGOの第一期観測(O1)が行われ、重力波イベントが2例検出されている（重力波源 GW 150914、GW151226）。J-GEM (Japanese collaboration of Gravitational wave Electro-Magnetic follow-up)グループとして事前に結んでいた覚書に基づき、これらの重力波天体の情報を受け取り、KWFCを用いて広域の突発天体探査観測を実施した。GW150914に関しては平成２７年度中に結果をまとめ、既に論文を出版している。平成２８年度はGW151226に対して行なったフォローアップ観測に関して、データ解析、突発天体検出と論文執筆を行なった。GW151226のアラート時の位置決定精度は約1400平方度であったが、KWFCでは778平方度に及ぶ広域探査を実行することができた。このデータを解析した結果、13個の銀河系外突発天体を発見した。Sloan Digital Sky Survey (SDSS)の撮像・分光データに基づき距離を算出したところ、そのうち6天体が、重力波から推定された距離の範囲内にあることが分かった。それらの突発天体の絶対等級は全て-19等程度であり、Ia型超新星ほどの明るさをもっていたため、6天体とも重力波天体ではないと結論づけた。これらの結果をJ-GEM全体のフォローアップ観測結果と一緒にまとめ、論文を出版した。
Deciphering the evolution of the Universe with wide-field survey and numerical cosmology

YOSHIDA Naoki, TANAKA Masaomi, HOSOKAWA Takashi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: The University of Tokyo

2013/04/01 - 2017/03/31

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We utilized data from Subaru FMOS and HSC surveys to study the structure formation in the Universe, and the nature of dark matter. In the beginning, we explored novel methods to probe the particle nature of dark matter and to detect distant galaxies. We then performed a number of cosmological simulations to generate mock galaxy catalogues. Toward the end of this research project, we analysed data from Subaru, combined with data from Fermi gamma-ray observatory and ALMA radio telescope, to place constraints on the annihilation cross-section of dark matter, to place constraints on the growth rate of large-scale structure, and to detect the most distant oxygen line emitter.
超高頻度サーベイ観測による短時間突発天体の検出

田中雅臣

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 新学術領域研究(研究領域提案型)

Institution: 国立天文台

2013/04/01 - 2015/03/31

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当初の計画通り、東京大学木曽観測所の1mシュミット望遠鏡と広視野カメラKWFC (Kiso Wide Field Camera)を用いて、高頻度の突発天体サーベイをKiso Supernova Survey (KISS)を推進した。平成25年度から本格的な遠隔・自動観測の整備を始め、平成26年度後半の観測からは完全に自動でサーベイが実行された。平成26年度は約100晩の観測の結果、37天体の超新星爆発候補天体を発見し、そのうち9天体の分光同定に成功した。フォローアップ分光に成功した天体数は平成25年度に比べて2倍程度増加している。サーベイの戦略と、約２年間の初期成果をまとめた論文をPublication of Astronomical Society of Japanに投稿し、出版した。また、高頻度の反復観測によって、特異な活動銀河核の短時間(~1日)変動を捉えた。すばる望遠鏡、国内の中小口径望遠鏡、さらにSwift衛星により追観測を行った結果、この天体が(1) 比較的軽いブラックホール質量(1E7太陽質量)をもつこと、(2)非常にradio loudであり(radio loudness parameter ~ 400-3000)、100kpcもの広がった電波の構造をもっていること、(3) Eddington光度に近いフラックスをもつことが分かった。これらの特徴から、この天体が急速に成長している途中のブラックホールをもち、かつ可視光の変動はジェットからの放射が原因であると解釈した。超新星の最初の瞬間（ショックブレイクアウト）を狙うサーベイ本来のターゲットではないものの、ユニークな高頻度の反復観測によって、新しい種類の現象が捉えられた例となった。この成果をまとめた論文をAstrophysical Journal Lettersに投稿し、出版した。
Studies of Supernovae by Large Surveys and Radiative Transfer Simulations

Tanaka Masaomi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Young Scientists (B)

Institution: National Astronomical Observatory of Japan

2012/04/01 - 2015/03/31

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To study the properties of massive stars just before the supernova explosion, we have performed high-cadence optical transient surveys. With the Subaru telescope and a wide field camera (Hyper Suprime-Cam), we have discovered luminous, rapidly rising transients, and suggested that some massive stars experience intensive mass loss just before the explosion. We have also developed a multi-dimensional, time-dependent, wavelength-dependent radiative transfer simulation code to give the direct comparison between supernova models and observations.
Understanding Massive Star Evolution and Explosion Mechanism of Supernovae

TANAKA Masaomi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Research Activity Start-up

Institution: National Astronomical Observatory of Japan

2010 - 2011

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We have developed a multi-dimensional radiative transfer code for supernova explosions including polarization, and simulated polarization spectra with various multi-dimensional ion distributions in supernova ejecta. We also performed spectropolarimetric observations of supernovae with Subaru telescope. Adding our new data to the existing datasets, we have constructed the largest data samples of Type Ibc supernovae. By comparing the results of simulations and observations, we showed that a three-dimensional geometry is common in supernovae.
超新星爆発とガンマ線バーストの発生機構の解明と超高赤方偏移宇宙の距離指標の確立

田中雅臣

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 特別研究員奨励費

Institution: 東京大学

2007 - 2009

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21年度は、昨年度から行っている重力崩壊型超新星の偏光観測を通して爆発のメカニズムに迫る研究をさらに発展させた。昨年度までに行った観測の結果、超新星の可視光スペクトル中のCa IIやFe IIのラインにおいて大きな偏光度が検出されていた。しかし、最新の観測では、これまでにない高い質のデータを取得することで、Ca IIやO I、He Iラインの波長で偏光の向きが一定でないことが発見された。これは、元素分布が決まった対称軸を持っておらず、大質量星が軸対称よりも複雑な3次元構造をもって爆発していることを意味している。通常、星は球対称(一次元)か、星の回転を考慮しても軸対称(二次元)に重力崩壊を起こすと考えられる。この観測の結果は、超新星爆発のメカニズムに三次元的な不安定性等が大きく関与していることを示唆しており、今後の大質量星崩壊の研究に新たな道筋を与えるものである。 Ia型超新星に関しても、すばる望遠鏡を用いて偏光分光観測を行った。Ia型超新星の中には極めて明るいものも存在し、チャンドラセカール限界質量を超えているものがあるのではないかと指摘されていた。しかし、その正体については決着がついておらず、爆発が非常に球対称からずれているために明るく見えているだけである、というシナリオも提唱されていた。今年度、このような極めて明るいIa型超新星の偏光分光観測に世界で初めて成功した。その結果、偏光度が他のIa型超新星と同程度に小さく、爆発は大きく歪んでいないことが判明した。この観測により、このような非常に明るいIa型超新星が、無回転時のチャンドラセカール限界質量を超えていることが確定的となった。

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