Kunihito IOKA

J-GLOBAL         Last updated: Jun 25, 2019 at 19:33
 
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Name
Kunihito IOKA
E-mail
kunihito.iokayukawa.kyoto-u.ac.jp
URL
http://www2.yukawa.kyoto-u.ac.jp/~kunihito.ioka/
Affiliation
Kyoto University
Degree
-(Kyoto University), -(Kyoto University)
ORCID ID
0000-0002-3517-1956

Research Interests

 
 

Research Areas

 
 

Academic & Professional Experience

 
Feb 2016
 - 
Today
Professor, Yukawa Institute for Theoretical Physics, Kyoto University
 
 
   
 
Associate Professor, High Energy Accelerator Research Organization Institute of Particle and Nuclear Studies
 
Apr 2004
 - 
Mar 2005
Postdoctoral Fellow, Pennsylvania State University
 

Education

 
 
 - 
2001
Graduate School, Division of Natural Science, Kyoto University
 
 
 - 
1996
Faculty of Science, Kyoto University
 

Published Papers

 
Monthly Notices of the Royal Astronomical Society      Jun 2019   [Refereed]
Kunihito Ioka, Amir Levinson, Ehud Nakar
Monthly Notices of the Royal Astronomical Society      Apr 2019   [Refereed]
Matsumoto Tatsuya, Ioka Kunihito, Kisaka Shota, Nakar Ehud
The Astrophysical Journal   861(1)    Jul 2018   [Refereed]
Tatsuya Matsumoto, Yuto Teraki, Kunihito Ioka
Monthly Notices of the Royal Astronomical Society   475(1) 1251-1260   Mar 2018   [Refereed]
Ioka Kunihito, Nakamura Takashi
PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS   (4)    Apr 2018   [Refereed]

Misc

 
Kunihito Ioka, Takashi Nakamura
   Mar 2019
Gravitational waves from a merger of two neutron stars (NSs) were discovered
for the first time in GW170817, together with diverse electromagnetic
counterparts, providing a direct clue to the origin of short gamma-ray bursts
(sGRBs). The associate...
Kunihito Ioka, Amir Levinson, Ehud Nakar
   Oct 2018
The breakout of a fast (Tex), yet sub-relativistic shock from a thick
stellar wind is expected to produce a pulse of X-rays with a rise time of
seconds to hours. Here we construct a semi-analytic model for the breakout of a
sub-relativistic, ...
Shigeo S. Kimura, Kohta Murase, Imre Bartos, Kunihito Ioka, Ik Siong Heng, Peter Mészáros
Phys. Rev. D 98, 043020 (2018)      May 2018
The observations of a macronova/kilonova accompanied by gravitational waves
from a binary neutron star merger (GW170817) confirmed that neutron star
coalescences produce copious ejecta. The coincident gamma-ray detection implies
the existence of a...
Tanmoy Laskar, Kate D. Alexander, Edo Berger, Cristiano Guidorzi, Raffaella Margutti, Wen-fai Fong, Charles D. Kilpatrick, Peter Milne, Maria R. Drout, C. G. Mundell, Shiho Kobayashi, Ragnhild Lunnan, Rodolfo Barniol Duran, Karl M. Menten, Kunihito Ioka, Peter K. G. Williams
Laskar et al 2018, ApJ, 862, 94      Aug 2018
We present detailed multi-wavelength observations of GRB 161219B at
Tex, spanning the radio to X-ray regimes, and the first ALMA light curve
of a GRB afterglow. The cm- and mm-band observations before Tex d require
emission in excess of t...
Ryo Yamazaki, Kunihito Ioka, Takashi Nakamura
Prog. Theor. Exp. Phys. 2018, 033E01      Nov 2017
The counter jet of a short gamma-ray burst (sGRB) has not yet been observed,
while recent discoveries of gravitational waves (GWs) from a binary neutron
star (NS) merger GW170817 and the associated sGRB 170817A have demonstrated
that off-axis sGRB...
Shota Kisaka, Kunihito Ioka, Kazumi Kashiyama, Takashi Nakamura
   Nov 2017
In the faint short gamma-ray burst sGRB 170817A followed by the gravitational
waves (GWs) from a merger of two neutron stars (NSs) GW170817, the spectral
peak energy is too high to explain only by canonical off-axis emission. We
investigate off-ax...
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
   Oct 2017
We perform a Tex-band survey for an optical counterpart of a binary neutron
star coalescence GW170817 with Subaru/Hyper Suprime-Cam. Our untargeted
transient search covers Tex degTex corresponding to the Tex credible
region of GW170817 an...
Kunihito Ioka, Takashi Nakamura
   Oct 2017
Gravitational waves from a merger of two neutron stars (NSs) were discovered
for the first time in GW170817, together with diverse electromagnetic (EM)
counterparts. To make constraints on a relativistic jet from the NS merger, we
calculate the EM...
Tatsuya Matsumoto, Daisuke Nakauchi, Kunihito Ioka, Kunihito Ioka, Kunihito Ioka, Takashi Nakamura
Astrophysical Journal   823    Jun 2016
© 2016. The American Astronomical Society. All rights reserved.Supermassive black holes observed at high redshift ≥ z 6 could grow from direct collapse black holes (DCBHs) with masses ∼ M 105 , which result from the collapse of supermassive stars ...
Kunihito Ioka, Kunihito Ioka, Kunihito Ioka, Kenta Hotokezaka, Tsvi Piran
Astrophysical Journal   833    Dec 2016
© 2016. The American Astronomical Society. All rights reserved.Ultra-long gamma-ray bursts (ulGRBs) are a new population of GRBs with extreme durations of ∼104 s. Leading candidates for their origin are blue supergiant collapsars, magnetars, and w...
F. Acero, R. Aloisio, R. Aloisio, J. Amans, E. Amato, L. A. Antonelli, C. Aramo, T. Armstrong, F. Arqueros, K. Asano, M. Ashley, M. Backes, C. Balazs, A. Balzer, A. Bamba, A. Bamba, M. Barkov, J. A. Barrio, W. Benbow, K. Bernlöhr, V. Beshley, C. Bigongiari, A. Biland, A. Bilinsky, E. Bissaldi, J. Biteau, O. Blanch, P. Blasi, J. Blazek, C. Boisson, G. Bonanno, A. Bonardi, C. Bonavolontà, G. Bonnoli, C. Braiding, S. Brau-Nogué, J. Bregeon, A. M. Brown, V. Bugaev, A. Bulgarelli, T. Bulik, M. Burton, A. Burtovoi, G. Busetto, M. Böttcher, R. Cameron, M. Capalbi, A. Caproni, P. Caraveo, R. Carosi, E. Cascone, M. Cerruti, S. Chaty, A. Chen, X. Chen, M. Chernyakova, M. Chikawa, J. Chudoba, J. Cohen-Tanugi, S. Colafrancesco, V. Conforti, J. L. Contreras, A. Costa, G. Cotter, S. Covino, G. Covone, P. Cumani, G. Cusumano, F. D'Ammando, D. D'Urso, M. Daniel, F. Dazzi, A. De Angelis, G. De Cesare, A. De Franco, F. De Frondat, E. M. De Gouveia Dal Pino, C. De Lisio, R. De Los Reyes Lopez, B. De Lotto, M. De Naurois, F. De Palma, M. Del Santo, C. Delgado, D. Della Volpe, T. Di Girolamo, C. Di Giulio, F. Di Pierro, L. Di Venere, M. Doro, J. Dournaux, D. Dumas, V. Dwarkadas, C. Díaz, J. Ebr, K. Egberts, S. Einecke, D. Elsässer, S. Eschbach, D. Falceta-Goncalves
Astrophysical Journal   840    May 2017
© 2017. The American Astronomical Society. All rights reserved.We perform simulations for future Cherenkov Telescope Array (CTA) observations of RX J1713.7-3946, a young supernova remnant (SNR) and one of the brightest sources ever discovered in v...
Y. Asaoka, Y. Asaoka, Y. Akaike, Y. Akaike, Y. Komiya, R. Miyata, S. Torii, S. Torii, S. Torii, O. Adriani, O. Adriani, O. Adriani, K. Asano, M. G. Bagliesi, M. G. Bagliesi, G. Bigongiari, G. Bigongiari, W. R. Binns, S. Bonechi, S. Bonechi, M. Bongi, M. Bongi, M. Bongi, P. Brogi, P. Brogi, J. H. Buckley, N. Cannady, G. Castellini, G. Castellini, G. Castellini, C. Checchia, M. L. Cherry, G. Collazuol, V. Di Felice, V. Di Felice, K. Ebisawa, H. Fuke, T. G. Guzik, T. Hams, T. Hams, M. Hareyama, N. Hasebe, K. Hibino, M. Ichimura, K. Ioka, W. Ishizaki, M. H. Israel, A. Javaid, K. Kasahara, J. Kataoka, R. Kataoka, Y. Katayose, C. Kato, N. Kawanaka, Y. Kawakubo, H. Kitamura, H. S. Krawczynski, J. F. Krizmanic, J. F. Krizmanic, S. Kuramata, T. Lomtadze, P. Maestro, P. Maestro, P. S. Marrocchesi, P. S. Marrocchesi, A. M. Messineo, J. W. Mitchell, S. Miyake, K. Mizutani, A. A. Moiseev, A. A. Moiseev, K. Mori, K. Mori, M. Mori, N. Mori, N. Mori, N. Mori, H. M. Motz, K. Munakata, H. Murakami, Y. E. Nakagawa, S. Nakahira, J. Nishimura, S. Okuno, J. F. Ormes, S. Ozawa, L. Pacini, L. Pacini, L. Pacini, F. Palma, F. Palma, P. Papini, P. Papini, P. Papini, A. V. Penacchioni, A. V. Penacchioni, B. F. Rauch, S. Ricciarini, S. Ricciarini, S. Ricciarini
Astroparticle Physics   91 1-10   May 2017
© 2017 The AuthorsIn August 2015, the CALorimetric Electron Telescope (CALET), designed for long exposure observations of high energy cosmic rays, docked with the International Space Station (ISS) and shortly thereafter began to collect data. CALE...
O. Adriani, O. Adriani, O. Adriani, Y. Akaike, Y. Akaike, K. Asano, Y. Asaoka, Y. Asaoka, M. G. Bagliesi, M. G. Bagliesi, G. Bigongiari, G. Bigongiari, W. R. Binns, S. Bonechi, S. Bonechi, M. Bongi, M. Bongi, M. Bongi, P. Brogi, P. Brogi, J. H. Buckley, N. Cannady, G. Castellini, G. Castellini, G. Castellini, C. Checchia, M. L. Cherry, G. Collazuol, V. Di Felice, V. Di Felice, K. Ebisawa, H. Fuke, T. G. Guzik, T. Hams, T. Hams, M. Hareyama, N. Hasebe, K. Hibino, M. Ichimura, K. Ioka, W. Ishizaki, M. H. Israel, A. Javaid, K. Kasahara, J. Kataoka, R. Kataoka, Y. Katayose, C. Kato, N. Kawanaka, Y. Kawakubo, H. Kitamura, H. S. Krawczynski, J. F. Krizmanic, J. F. Krizmanic, S. Kuramata, T. Lomtadze, P. Maestro, P. Maestro, P. S. Marrocchesi, P. S. Marrocchesi, A. M. Messineo, J. W. Mitchell, S. Miyake, K. Mizutani, A. A. Moiseev, A. A. Moiseev, K. Mori, K. Mori, M. Mori, N. Mori, N. Mori, N. Mori, H. M. Motz, K. Munakata, H. Murakami, Y. E. Nakagawa, S. Nakahira, J. Nishimura, S. Okuno, J. F. Ormes, S. Ozawa, L. Pacini, L. Pacini, L. Pacini, F. Palma, F. Palma, P. Papini, P. Papini, P. Papini, A. V. Penacchioni, A. V. Penacchioni, B. F. Rauch, S. Ricciarini, S. Ricciarini, S. Ricciarini, K. Sakai, K. Sakai, T. Sakamoto, M. Sasaki, M. Sasaki
Astrophysical Journal Letters   829    Sep 2016
© 2016. The American Astronomical Society. All rights reserved..We present upper limits in the hard X-ray and gamma-ray bands at the time of the Laser Interferometer Gravitational-wave Observatory (LIGO) gravitational-wave event GW151226 derived f...
Yutaka Ohira, Norita Kawanaka, Kunihito Ioka, Kunihito Ioka
Physical Review D   93    Apr 2016
© 2016 American Physical Society.Recent precise observations of cosmic rays (CRs) by AMS-02 experiment clearly show (1) harder spectra of helium and carbon compared to protons by R0.08, and (2) concave breaks in proton and helium spectra at a rigi...
Koutarou Kyutoku, Kunihito Ioka, Kunihito Ioka, Kunihito Ioka
Astrophysical Journal   827    Aug 2016
© 2016. The American Astronomical Society. All rights reserved..We reach the robust conclusion that, by combining the observed cosmic rays of r-process elements with the fact that the velocity of the neutron-star-merger ejecta is much higher than ...
Yasuaki Kagawa, Daisuke Yonetoku, Tatsuya Sawano, Asuka Toyanago, Takashi Nakamura, Keitaro Takahashi, Kazumi Kashiyama, Kunihito Ioka, Kunihito Ioka
Astrophysical Journal   811    Sep 2015
© 2015. The American Astronomical Society. All rights reserved..Extended emission in short gamma-ray bursts (SGRBs) is a mystery. By conducting time-resolved spectral analyses of the nine brightest events observed by the Swift-XRT, we classify the...
Shota Kisaka, Kunihito Ioka, Kunihito Ioka, Ehud Nakar
Astrophysical Journal   818    Feb 2016
© 2016. The American Astronomical Society. All rights reserved..A macronova (or kilonova) was observed as an infrared excess several days after the short gamma-ray burst GRB 130603B. Although the r-process radioactivity is widely discussed as an e...
Tatsuya Matsumoto, Daisuke Nakauchi, Daisuke Nakauchi, Kunihito Ioka, Kunihito Ioka, Alexander Heger, Alexander Heger, Alexander Heger, Takashi Nakamura
Astrophysical Journal   810    Sep 2015
The existence of black holes (BHs) of mass ∼109 M⊙ at z ≳ 6 is a big puzzle in astrophysics because even optimistic estimates of the accretion time are insufficient for stellar-mass BHs of ∼10 M⊙ to grow into such supermassive BHs. A resolution of...
Kazunori Kohri, Kunihito Ioka, Yutaka Fujita, Ryo Yamazaki, Ryo Yamazaki
Progress of Theoretical and Experimental Physics   2016    Feb 2016
© The Author(s) 2016.We explain the excess of the antiproton fraction recently reported by the AMS-02 experiment by considering collisions between cosmic-ray protons accelerated by a local supernova remnant and the surrounding dense cloud. The sam...
Koutarou Kyutoku, Koutarou Kyutoku, Kunihito Ioka, Kunihito Ioka, Hirotada Okawa, Hirotada Okawa, Masaru Shibata, Keisuke Taniguchi, Keisuke Taniguchi
Physical Review D - Particles, Fields, Gravitation and Cosmology   92    Aug 2015
© 2015 American Physical Society.We investigate properties of material ejected dynamically in the merger of black hole-neutron star binaries by numerical-relativity simulations. We systematically study the dependence of ejecta properties on the ma...
Norita Kawanaka, Kunihito Ioka, Kunihito Ioka
Physical Review D - Particles, Fields, Gravitation and Cosmology   92    Oct 2015
© 2015 American Physical Society.Acceleration of π's and μ's modifies the flavor ratio at Earth (at astrophysical sources) of neutrinos produced by π decay, νeνμ ντ, from 111 (120) to 11.81.8 (010) at high energy, because π's decay more than μ's d...
Shota Kisaka, Kunihito Ioka, Kunihito Ioka, Takashi Nakamura
Astrophysical Journal Letters   809    Aug 2015
© 2015. The American Astronomical Society. All rights reserved.Neutron star binary mergers are strong sources of gravitational waves (GWs). Promising electromagnetic counterparts are short gamma-ray bursts (GRBs), but the emission is highly collim...
Shunsaku Horiuchi, Kohta Murase, Kunihito Ioka, Peter Meszaros
Astrophys.J.753:69,2012   753    Mar 2012
Heavy nuclei such as nickel-56 are synthesized in a wide range of
core-collapse supernovae (CCSN), including energetic supernovae associated with
gamma-ray bursts (GRBs). Recent studies suggest that jet-like outflows are a
common feature of CCSN. ...
Masato Yamanaka, Masato Yamanaka, Kazunori Kohri, Kazunori Kohri, Kunihito Ioka, Kunihito Ioka, Mihoko M. Nojiri, Mihoko M. Nojiri
Physical Review D - Particles, Fields, Gravitation and Cosmology   91    Mar 2015
© 2015 American Physical Society.We apply the axion-photon conversion mechanism to the 130 GeV γ-ray line observed by the Fermi satellite. Near the Galactic center, some astrophysical sources and/or particle dark matter can produce energetic axion...
Masaru Shibata, Yudai Suwa, Kenta Kiuchi, Kunihito Ioka
Astrophysical Journal Letters   734    Jun 2011
The merger of two neutron stars often results in a rapidly and differentially rotating hypermassive neutron star (HMNS). We show by numerical-relativity simulation that the magnetic-field profile around such HMNS is dynamically varied during its s...
O. Adriani, Y. Akaike, K. Asano, Y. Asaoka, M. G. Bagliesi, G. Bigongiari, W. R. Binns, S. Bonechi, M. Bongi, J. H. Buckley, G. Castellini, M. L. Cherry, G. Collazuol, K. Ebisawa, V. Di Felice, H. Fuke, T. G. Guzik, T. Hams, M. Hareyama, N. Hasebe, K. Hibino, M. Ichimura, K. Ioka, M. H. Israel, A. Javaid, E. Kamioka, K. Kasahara, J. Kataoka, R. Kataoka, Y. Katayose, N. Kawanaka, H. Kitamura, T. Kotani, H. S. Krawczynski, J. F. Krizmanic, A. Kubota, S. Kuramata, T. Lomtadze, P. Maestro, L. Marcelli, P. S. Marrocchesi, J. W. Mitchell, S. Miyake, K. Mizutani, A. A. Moiseev, K. Mori, K. Mori, M. Mori, N. Mori, H. M. Motz, K. Munakata, H. Murakami, Y. E. Nakagawa, S. Nakahira, J. Nishimura, S. Okuno, J. F. Ormes, S. Ozawa, F. Palma, P. Papini, B. F. Rauch, S. B. Ricciarini, T. Sakamoto, M. Sasaki, M. Shibata, Y. Shimizu, A. Shiomi, R. Sparvoli, P. Spillantini, I. Takahashi, M. Takayanagi, M. Takita, T. Tamura, T. Tamura, N. Tateyama, T. Terasawa, H. Tomida, S. Torii, S. Torii, Y. Tunesada, Y. Uchihori, S. Ueno, E. Vannuccini, J. P. Wefel, K. Yamaoka, S. Yanagita, A. Yoshida, K. Yoshida, T. Yuda
EPJ Web of Conferences   95    May 2015
© Owned by the authors, published by EDP Sciences, 2015.The CALorimetric Electron Telescope (CALET) is a space experiment, currently under development by Japan in collaboration with Italy and the United States, which will measure the flux of cosmi...
Shota Kisaka, Kunihito Ioka, Kunihito Ioka, Hajime Takami
Astrophysical Journal   802    Apr 2015
© 2015. The American Astronomical Society. All rights reserved.A macronova (kilonova) was discovered with a short gamma-ray burst, GRB 130603B, which is widely believed to be powered by the radioactivity of r-process elements synthesized in the ej...
Shota Kisaka, Kunihito Ioka, Kunihito Ioka
Astrophysical Journal Letters   804    May 2015
© 2015. The American Astronomical Society. All rights reserved.Whether a short gamma-ray burst (GRB) is caused by a black hole (BH) or a neutron star (NS) after the merger of an NS binary is a crucial problem. We propose a BH model that explains s...
Rafael S de Souza, Naoki Yoshida, Kunihito Ioka
A&A, 533, A32 (2011)   533    May 2011
We calculate the theoretical event rate of gamma-ray bursts (GRBs) from the
collapse of massive first-generation (Population III; Pop III) stars. The Pop
III GRBs could be super-energetic with the isotropic energy up to $E_{\rm iso}
\gtrsim 10^{55...
Qiang Yuan, Qiang Yuan, Kunihito Ioka, Kunihito Ioka
Astrophysical Journal   802    Apr 2015
© 2015. The American Astronomical Society. All rights reserved.Recent analyses of Fermi Large Area Telescope data show an extended GeV γ-ray excess on top of the expected diffuse background in the Galactic center region, which can be explained by ...
Tsuyoshi Inoue, Tsuyoshi Inoue, Katsuaki Asano, Kunihito Ioka
Astrophysical Journal   734    Jun 2011
Relativistic astrophysical phenomena such as gamma-ray bursts (GRBs) and active galactic nuclei often require long-lived strong magnetic fields that cannot be achieved by shock compression alone. Here, we report on three-dimensional special-relati...
T. Nakamori, H. Katagiri, H. Sano, R. Yamazaki, Y. Ohira, A. Bamba, Y. Fukui, K. Mori, S. H. Lee, Y. Fujita, H. Tajima, T. Inoue, S. Gunji, Y. Hanabata, M. Hayashida, H. Kubo, J. Kushida, S. Inoue, K. Ioka, K. Kohri, K. Murase, S. Nagataki, T. Naito, A. Okumura, A. Okumura, A. Okumura, T. Saito, M. Sawada, T. Tanaka, Y. Terada, Y. Uchiyama, S. Yanagita, T. Yoshida, T. Yoshikoshi
Proceedings of Science   30-July-2015    Jan 2015
We perform simulations of Cherenkov Telescope Array (CTA) observations of a young supernova remnant RX J1713.7-3946. This target is not only one of the brightest sources ever discovered in very high-energy (VHE) gamma rays but also well observed i...
Kunihito Ioka, Yudai Suwa, Hiroki Nagakura, Rafael S. De Souza, Naoki Yoshida
Proceedings of the International Astronomical Union   7 301-304   Apr 2011
Gamma-ray bursts (GRBs) are unique probes of the first generation (Pop III) stars. We show that a relativistic gamma-ray burst (GRB) jet can potentially pierce the envelope of a very massive Pop III star even if the Pop III star has a supergiant h...
Hiroki Nagakura, Hiroki Nagakura, Yudai Suwa, Kunihito Ioka
Proceedings of the International Astronomical Union   7 363-364   Apr 2011
We investigate the propagation of accretion-powered jets in various types of progenitor candidates of GRBs. We perform two dimensional axisymmetric simulations of relativistic hydrodynamics taking into account both the envelope collapse and the je...
Yutaka Ohira, Kunihito Ioka
Astrophysical Journal Letters   729    Mar 2011
Recent observations by the CREAM and ATIC-2 experiments suggest that (1) the spectrum of cosmic-ray (CR) helium is harder than that of CR protons below the knee energy, 1015eV, and (2) all CR spectra become hard at ≳1011eV nucleon-1. We propose a ...
Kazumi Kashiyama, Kunihito Ioka
Phys.Rev.D83:081302,2011   83    Feb 2011
Magnetic flares and induced oscillations of magnetars (super-magnetized
neutron stars) are promising sources of gravitational waves (GWs). We suggest
that the GW emission, if any, would last longer than the observed X-ray
quasi-periodic oscillatio...
O. Adriani, Y. Akaike, K. Asano, Y. Asaoka, M. G. Bagliesi, G. Bigongiari, W. R. Binns, S. Bonechi, M. Bongi, J. H. Buckley, G. Castellini, M. L. Cherry, G. Collazuol, K. Ebisawa, V. Di Felice, H. Fuke, T. G. Guzik, T. Hams, M. Hareyama, N. Hasebe, K. Hibino, M. Ichimura, K. Ioka, M. H. Israel, A. Javaid, E. Kamioka, K. Kasahara, J. Kataoka, R. Kataoka, Y. Katayose, N. Kawanaka, H. Kitamura, T. Kotani, H. S. Krawczynski, J. F. Krizmanic, A. Kubota, S. Kuramata, T. Lomtadze, P. Maestro, L. Marcelli, P. S. Marrocchesi, J. W. Mitchell, S. Miyake, K. Mizutani, A. A. Moiseev, K. Mori, K. Mori, M. Mori, N. Mori, H. M. Motz, K. Munakata, H. Murakami, Y. E. Nakagawa, S. Nakahira, J. Nishimura, S. Okuno, J. F. Ormes, S. Ozawa, F. Palma, P. Papini, B. F. Rauch, S. B. Ricciarini, S. B. Ricciarini, T. Sakamoto, M. Sasaki, M. Shibata, Y. Shimizu, A. Shiomi, R. Sparvoli, P. Spillantini, I. Takahashi, M. Takayanagi, M. Takita, T. Tamura, T. Tamura, N. Tateyama, T. Terasawa, H. Tomida, S. Torii, S. Torii, Y. Tunesada, Y. Uchihori, S. Ueno, E. Vannuccini, J. P. Wefel, K. Yamaoka, S. Yanagita, A. Yoshida, K. Yoshida, T. Yuda
Journal of Physics: Conference Series   632    Jan 2015
© Published under licence by IOP Publishing Ltd.The CALorimetric Electron Telescope (CALET) is a space experiment, currently under development by Japan in collaboration with Italy and the United States, which will measure the flux of cosmic-ray el...
Seiji Kawamura, Seiji Kawamura, Masaki Ando, Naoki Seto, Shuichi Sato, Takashi Nakamura, Kimio Tsubono, Nobuyuki Kanda, Takahiro Tanaka, Jun'Ichi Yokoyama, Ikkoh Funaki, Kenji Numata, Kunihito Ioka, Takeshi Takashima, Kazuhiro Agatsuma, Tomotada Akutsu, Koh Suke Aoyanagi, Koji Arai, Akito Araya, Hideki Asada, Yoichi Aso, Dan Chen, Takeshi Chiba, Toshikazu Ebisuzaki, Yumiko Ejiri, Motohiro Enoki, Yoshiharu Eriguchi, Masa Katsu Fujimoto, Ryuichi Fujita, Mitsuhiro Fukushima, Toshifumi Futamase, Tomohiro Harada, Tatsuaki Hashimoto, Kazuhiro Hayama, Wataru Hikida, Yoshiaki Himemoto, Hisashi Hirabayashi, Takashi Hiramatsu, Feng Lei Hong, Hideyuki Horisawa, Mizuhiko Hosokawa, Kiyotomo Ichiki, Takeshi Ikegami, Kaiki T. Inoue, Koji Ishidoshiro, Hideki Ishihara, Takehiko Ishikawa, Hideharu Ishizaki, Hiroyuki Ito, Yousuke Itoh, Kiwamu Izumi, Isao Kawano, Nobuki Kawashima, Fumiko Kawazoe, Naoko Kishimoto, Kenta Kiuchi, Shiho Kobayashi, Kazunori Kohri, Hiroyuki Koizumi, Yasufumi Kojima, Keiko Kokeyama, Wataru Kokuyama, Kei Kotake, Yoshihide Kozai, Hiroo Kunimori, Hitoshi Kuninaka, Kazuaki Kuroda, Sachiko Kuroyanagi, Kei Ichi Maeda, Hideo Matsuhara, Nobuyuki Matsumoto, Yuta Michimura, Osamu Miyakawa, Umpei Miyamoto, Shinji Miyoki, Mutsuko Y. Morimoto, Toshiyuki Morisawa, Shigenori Moriwaki, Shinji Mukohyama, Mitsuru Musha, Shigeo Nagano, Isao Naito, Kouji Nakamura, Hiroyuki Nakano, Kenichi Nakao, Shinichi Nakasuka, Yoshinori Nakayama, Kazuhiro Nakazawa, Erina Nishida, Kazutaka Nishiyama, Atsushi Nishizawa, Yoshito Niwa, Taiga Noumi, Yoshiyuki Obuchi, Masatake Ohashi, Naoko Ohishi, Naoko Ohishi, Masashi Ohkawa, Kenshi Okada, Norio Okada
Classical and Quantum Gravity   28    May 2011
The objectives of the DECi-hertz Interferometer Gravitational Wave Observatory (DECIGO) are to open a new window of observation for gravitational wave astronomy and to obtain insight into significant areas of science, such as verifying and charact...
Yutaka Ohira, Kunihito Ioka
Proceedings of the 32nd International Cosmic Ray Conference, ICRC 2011   6 206-209   Jan 2011
Recent observations by the ATIC-2, CREAM and PAMELA experiments suggest that the spectrum of cosmicray (CR) helium is harder than that of CR protons below the knee energy and all CR spectra become hard at 100 GeV/nucleon. According to DSA theory, ...
Kunihito Ioka
Prog. Theor. Phys. 124 (2010), 667-710   124 667-710   Jun 2010
Collisionless entrainment of the surrounding matter imports the relativistic
baryon component in the Gamma-Ray Burst (GRB) fireball frame. We show that half
the fireball energy can be transferred from radiation to the comoving hot
motions of baryo...
Kunihito Ioka
AIP Conference Proceedings   1279 28-31   Dec 2010
Collisionless entrainment of the surrounding matter imports the relativistic baryon component in the Gamma-Ray Burst (GRB) fireball frame. We show that half the fireball energy can be transferred from radiation to the comoving hot motions of baryo...
K. Toma, T. Sakamoto, T. Sakamoto, B. Zhang, J. E. Hill, J. E. Hill, M. L. McConnell, P. E. Bloser, R. Yamazaki, K. Ioka, T. Nakamura
AIP Conference Proceedings   1133 434-436   Nov 2009
The emission mechanism and the origin and structure of magnetic fields in gamma-ray burst (GRB) jets are among the most important open questions concerning the nature of the central engine of GRBs. In spite of extensive observational efforts, thes...
Kenji Toma, Takanori Sakamoto, Bing Zhang, Joanne E. Hill, Mark L. McConnell, Peter F. Bloser, Ryo Yamazaki, Kunihito Ioka, Takashi Nakamura
Astrophys.J.698:1042-1053,2009   698 1042-1053   Dec 2008
The emission mechanism and the origin and structure of magnetic fields in
gamma-ray burst (GRB) jets are among the most important open questions
concerning the nature of the central engine of GRBs. In spite of extensive
observational efforts, thes...
Yutaka Fujita, Kazunori Kohri, Ryo Yamazaki, Kunihito Ioka
Phys.Rev.D80:063003,2009   80    Mar 2009
We show that the anomaly of the positron fraction observed by the PAMELA
experiment can be attributed to recent supernova explosion(s) in a dense gas
cloud (DC) near the Earth. Protons are accelerated around the supernova remnant
(SNR). Electrons ...
M. Ohno, K. Ioka, M. Kokubun, M. Suzuki, T. Takahashi, T. Uehara, T. Takahashi, Y. Fukazawa, C. Kira, Y. Hanabata, K. Yamaoka, S. Sugita, Y. Terada, Y. Urata, K. Onda, N. Kodaka, A. E. Morigami, T. Sugasahara, W. Iwakiri, M. S. Tashiro, Y. E. Nakagawa, T. Tamagawa, T. Enoto, K. Nakazawa, K. Makishima, E. Sonoda, M. Yamauchi, H. Tanaka, R. Hara, N. Ohmori, K. Kono, H. Hayasi, S. Hong
AIP Conference Proceedings   1133 338-343   Nov 2009
Although the afterglow observations in HETE-2 and Swift era have revealed a lot of afterglow properties of gammaray bursts (GRBs), we still have poor understanding of the prompt gamma-ray emission, such as the emission mechanism of the prompt emis...
Satoshi Okuzumi, Kunihito Ioka, Masa Aki Sakagami
Journal of Physics: Conference Series   154    Jun 2009
We discuss the nonlinear evolution of black hole ringdown in the framework of higher-order metric perturbation theory. By solving the initial-value problem of a simplified nonlinear field model analytically as well as numerically, we find that (i)...
Kohta Murase, Kenji Toma, Ryo Yamazaki, Shigehiro Nagataki, Kunihito Ioka
Mon.Not.Roy.Astron.Soc. 402 (2010) L54   402    Oct 2009
We study high-energy gamma-ray afterglow emission from gamma-ray bursts
(GRBs) in the prior emission model, which is proposed to explain the plateau
phase of the X-ray afterglow. This model predicts the high-energy gamma-ray
emission when the prom...
Shuichi Sato, Seiji Kawamura, Masaki Ando, Takashi Nakamura, Kimio Tsubono, Akito Araya, Ikkoh Funaki, Kunihito Ioka, Nobuyuki Kanda, Shigenori Moriwaki, Mitsuru Musha, Kazuhiro Nakazawa, Kenji Numata, Shin Ichiro Sakai, Naoki Seto, Takeshi Takashima, Takahiro Tanaka, Kazuhiro Agatsuma, Koh Suke Aoyanagi, Koji Arai, Hideki Asada, Yoichi Aso, Takeshi Chiba, Toshikazu Ebisuzaki, Yumiko Ejiri, Motohiro Enoki, Yoshiharu Eriguchi, Masa Katsu Fujimoto, Ryuichi Fujita, Mitsuhiro Fukushima, Toshifumi Futamase, Katsuhiko Ganzu, Tomohiro Harada, Tatsuaki Hashimoto, Kazuhiro Hayama, Wataru Hikida, Yoshiaki Himemoto, Hisashi Hirabayashi, Takashi Hiramatsu, Feng Lei Hong, Hideyuki Horisawa, Mizuhiko Hosokawa, Kiyotomo Ichiki, Takeshi Ikegami, Kaiki TInoue, Koji Ishidoshiro, Hideki Ishihara, Takehiko Ishikawa, Hideharu Ishizaki, Hiroyuki Ito, Yousuke Itoh, Nobuki Kawashima, Fumiko Kawazoe, Kishimoto Naoko, Kenta Kiuchi, Shiho Kobayashi, Kazunori Kohri, Hiroyuki Koizumi, Yasufumi Kojima, Keiko Kokeyama, Wataru Kokuyama, Kei Kotake, Yoshihide Kozai, Hideaki Kudoh, Hiroo Kunimori, Hitoshi Kuninaka, Kazuaki Kuroda, Kei Ichi Maeda, Hideo Matsuhara, Yasushi Mino, Osamu Miyakawa, Shinji Miyoki, Mutsuko YMorimoto, Tomoko Morioka, Toshiyuki Morisawa, Shinji Mukohyama, Shigeo Nagano, Isao Naito, Kouji Nakamura, Hiroyuki Nakano, Kenichi Nakao, Shinichi Nakasuka, Yoshinori Nakayama, Erina Nishida, Kazutaka Nishiyama, Atsushi Nishizawa, Yoshito Niwa, Taiga Noumi, Yoshiyuki Obuchi, Masatake Ohashi, Naoko Ohishi, Masashi Ohkawa, Norio Okada, Kouji Onozato, Kenichi Oohara, Norichika Sago, Motoyuki Saijo, Masaaki Sakagami, Shihori Sakata, Misao Sasaki
Journal of Physics: Conference Series   154    Jun 2009
DECi-hertz Interferometer Gravitational wave Observatory (DECIGO) is the planned Japanese space gravitational wave antenna, aiming to detect gravitational waves from astrophysically and cosmologically significant sources mainly between 0.1 Hz and ...
Junichi Aoi, Kohta Murase, Keitaro Takahashi, Kunihito Ioka, Shigehiro Nagataki
Astrophysical Journal722:440-451, 2010   722 440-451   May 2009
We revisit the high-energy spectral cutoff originating from the
electron-positron pair creation in the prompt phase of gamma-ray bursts (GRBs)
with numerical and analytical calculations. We show that the conventional
exponential and/or broken powe...
Masaki Ando, Seiji Kawamura, Shuichi Sato, Takashi Nakamura, Kimio Tsubono, Akito Araya, Ikkoh Funaki, Kunihito Ioka, Nobuyuki Kanda, Shigenori Moriwaki, Mitsuru Musha, Kazuhiro Nakazawa, Kenji Numata, Shin Ichiro Sakai, Naoki Seto, Takeshi Takashima, Takahiro Tanaka, Kazuhiro Agatsuma, Koh Suke Aoyanagi, Koji Arai, Hideki Asada, Yoichi Aso, Takeshi Chiba, Toshikazu Ebisuzaki, Yumiko Ejiri, Motohiro Enoki, Yoshiharu Eriguchi, Masa Katsu Fujimoto, Ryuichi Fujita, Mitsuhiro Fukushima, Toshifumi Futamase, Katsuhiko Ganzu, Tomohiro Harada, Tatsuaki Hashimoto, Kazuhiro Hayama, Wataru Hikida, Yoshiaki Himemoto, Hisashi Hirabayashi, Takashi Hiramatsu, Feng Lei Hong, Hideyuki Horisawa, Mizuhiko Hosokawa, Kiyotomo Ichiki, Takeshi Ikegami, Kaiki T. Inoue, Koji Ishidoshiro, Hideki Ishihara, Takehiko Ishikawa, Hideharu Ishizaki, Hiroyuki Ito, Yousuke Itoh, Nobuki Kawashima, Fumiko Kawazoe, Naoko Kishimoto, Kenta Kiuchi, Shiho Kobayashi, Kazunori Kohri, Hiroyuki Koizumi, Yasufumi Kojima, Keiko Kokeyama, Wataru Kokuyama, Kei Kotake, Yoshihide Kozai, Hideaki Kudoh, Hiroo Kunimori, Hitoshi Kuninaka, Kazuaki Kuroda, Kei Ichi Maeda, Hideo Matsuhara, Yasushi Mino, Osamu Miyakawa, Shinji Miyoki, Mutsuko Y. Morimoto, Tomoko Morioka, Toshiyuki Morisawa, Shinji Mukohyama, Shigeo Nagano, Isao Naito, Kouji Nakamura, Hiroyuki Nakano, Kenichi Nakao, Shinichi Nakasuka, Yoshinori Nakayama, Erina Nishida, Kazutaka Nishiyama, Atsushi Nishizawa, Yoshito Niwa, Taiga Noumi, Yoshiyuki Obuchi, Masatake Ohashi, Naoko Ohishi, Masashi Ohkawa, Norio Okada, Kouji Onozato, Kenichi Oohara, Norichika Sago, Motoyuki Saijo, Masaaki Sakagami, Shihori Sakata, Misao Sasaki
Classical and Quantum Gravity   26    May 2009
DECIGO pathfinder (DPF) is a milestone satellite mission for DECIGO (DECihertz Interferometer Gravitational wave Observatory), which is a future space gravitational wave antenna. DECIGO is expected to provide fruitful insights into the universe, p...
Masanori Ohno, Kunihito Ioka, Kazutaka Yamaoka, Makoto Tashiro, Yasushi Fukazawa, Yujin E. Nakagawa
Publications of the Astronomical Society of Japan   61 201-211   Apr 2009
We performed a time-resolved spectral analysis of a bright, long gamma-ray burst GRB 061007 using Suzaku/WAM and Swift/BAT. Because of the large effective area of the WAM, we can investigate the time evolution of the spectral peak energy and the l...
Ioka Kunihito, Ioka Kunihito, Kohta Murase, Kenji Toma, Shigehiro Nagataki, Takashi Nakamura
Astrophysical Journal   670    Dec 2007
We propose an emission mechanism of prompt gamma-ray bursts (GRBs) that can reproduce the observed nonthermal spectra with high radiative efficiencies, >50%. Internal dissipation below a photosphere can create a radiation-dominated thermal firebal...
Satoshi Okuzumi, Kunihito Ioka, Masa-aki Sakagami
Phys.Rev.D77:124018,2008   77    Mar 2008
We investigate the nonlinear evolution of black hole ringdown in the
framework of higher-order metric perturbation theory. By solving the
initial-value problem of a simplified nonlinear field model analytically as
well as numerically, we find that...
M. L. McConnell, L. Angelini, M. G. Baring, S. Barthelmy, J. K. Black, P. F. Bloser, B. Dennis, A. G. Emslie, J. Greiner, W. Hajdas, A. K. Harding, D. H. Hartmann, J. E. Hill, J. E. Hill, K. Ioka, P. Kaaret, G. Kanbach, D. Kniffen, J. S. Legere, J. R. Macri, R. Morris, T. Nakamura, N. Produit, J. M. Ryan, T. Sakamoto, K. Toma, X. Wu, R. Yamazaki, B. Zhang
AIP Conference Proceedings   1133 64-66   Nov 2009
POET (Polarimeters for Energetic Transients) represents a concept for a Small Explorer (SMEX) satellite mission, whose principal scientific goal is to understand the structure of GRB sources through sensitive X-ray and ?-ray polarization measureme...
Kohta Murase, Kunihito Ioka, Shigehiro Nagataki, Takashi Nakamura
Phys.Rev.D 78 (2008) 023005   78    Jan 2008
Gamma-ray bursts (GRBs) are one of the candidates of ultra-high-energy
(around 10^18.5 eV) cosmic-ray (UHECR) sources. We investigate high-energy
cosmic-ray acceleration including heavy nuclei in GRBs by using Geant 4, and
discuss its various impl...
Kazumi Kashiyama, Kunihito Ioka
AIP Conference Proceedings   1279 352-354   Dec 2010
We suggest that white dwarf pulsars can compete with neutron star pulsars for producing the excesses of cosmic ray positrons and electrons (e ±) observed by the PAMELA, ATIC/PPB-BETS, Fermi and HESS experiments. A double de...
Masaki Ando, Seiji Kawamura, Naoki Seto, Shuichi Sato, Takashi Nakamura, Kimio Tsubono, Takeshi Takashima, Ikkoh Funaki, Kenji Numata, Nobuyuki Kanda, Takahiro Tanaka, Kunihito Ioka, Kazuhiro Agatsuma, Koh Suke Aoyanagi, Koji Arai, Akito Araya, Hideki Asada, Yoichi Aso, Takeshi Chiba, Toshikazu Ebisuzaki, Yumiko Ejiri, Motohiro Enoki, Yoshiharu Eriguchi, Masa Katsu Fujimoto, Ryuichi Fujita, Mitsuhiro Fukushima, Toshifumi Futamase, Tomohiro Harada, Tatsuaki Hashimoto, Kazuhiro Hayama, Wataru Hikida, Yoshiaki Himemoto, Hisashi Hirabayashi, Takashi Hiramatsu, Feng Lei Hong, Hideyuki Horisawa, Mizuhiko Hosokawa, Kiyotomo Ichiki, Takeshi Ikegami, Kaiki T. Inoue, Koji Ishidoshiro, Hideki Ishihara, Takehiko Ishikawa, Hideharu Ishizaki, Hiroyuki Ito, Yousuke Itoh, Kiwamu Izumi, Isao Kawano, Nobuki Kawashima, Fumiko Kawazoe, Naoko Kishimoto, Kenta Kiuchi, Shiho Kobayashi, Kazunori Kohri, Hiroyuki Koizumi, Yasufumi Kojima, Keiko Kokeyama, Wataru Kokuyama, Kei Kotake, Yoshihide Kozai, Hiroo Kunimori, Hitoshi Kuninaka, Kazuaki Kuroda, Kei Ichi Maeda, Hideo Matsuhara, Yasushi Mino, Osamu Miyakawa, Umpei Miyamoto, Shinji Miyoki, Mutsuko Y. Morimoto, Toshiyuki Morisawa, Shigenori Moriwaki, Shinji Mukohyama, Mitsuru Musha, Shigeo Nagano, Isao Naito, Kouji Nakamura, Masahiro Nakamura, Hiroyuki Nakano, Kenichi Nakao, Shinichi Nakasuka, Yoshinori Nakayama, Kazuhiro Nakazawa, Erina Nishida, Kazutaka Nishiyama, Atsushi Nishizawa, Yoshito Niwa, Taiga Noumi, Yoshiyuki Obuchi, Masatake Ohashi, Naoko Ohishi, Masashi Ohkawa, Kenshi Okada, Norio Okada, Kenichi Oohara, Norichika Sago, Motoyuki Saijo, Ryo Saito, Masaaki Sakagami, Shin Ichiro Sakai
Classical and Quantum Gravity   27    Apr 2010
A space gravitational-wave antenna, DECIGO (DECI-hertz interferometer Gravitational wave Observatory), will provide fruitful insights into the universe, particularly on the formation mechanism of supermassive black holes, dark energy and the infla...
Yudai Suwa, Kunihito Ioka
AIP Conference Proceedings   1279 187-190   Dec 2010
We discuss the relativistic jet propagation in the envelope of very massive first generation star (Population III; Pop III). By using a density profile of the Pop III star for estimating the jet luminosity and its penetrability, we show that the r...
Kenji Toma, Kunihito Ioka, Takashi Nakamura
Astrophys.J. 673 (2008) L123-L126   673    Sep 2007
The late-time optical/radio afterglows of Tex-ray bursts (GRBs) are
believed to be synchrotron emission of electrons accelerated in relativistic
collisionless shocks propagating in the ambient medium of the sources. However,
the fraction Tex ...
Norita Kawanaka, Kunihito Ioka, Mihoko M. Nojiri
Astrophys.J.710:958-963,2010   710 958-963   Mar 2009
We investigate the observed spectrum of cosmic-ray electrons and positrons
from astrophysical sources, especially pulsars, and the physical processes for
making the spectrum spiky or smooth via continuous and multiple
electron/positron injections....
Norita Kawanaka, Kunihito Ioka, Yutaka Ohira, Kazumi Kashiyama
Astrophys.J.729:93,2011   729    Sep 2010
One of the most essential but uncertain processes for producing cosmic-rays
(CRs) and their spectra is how accelerated particles escape into the
interstellar space. We propose that the CR electron spectra at >~TeV energy can
provide a direct probe...
Kunihito Ioka, Yutaka Ohira, Norita Kawanaka, Akira Mizuta
Prog. Theor. Phys. 126 (2011), 555-564   126 555-564   Mar 2011
We show that, contrary to common belief, internal shocks can arise in an
accelerating radiation-dominated jet if it is confined even weakly to a
converging opening angle because the acceleration declines. The
radiation-dominated internal shock (RD...
Yuji Urata, Kui Yun Huang, Ping Hung Kuo, Wing Huen Ip, Yulei Qiu, Keisuke Masuno, Makoto Tashiro, Keiichi Abe, Kaori Onda, Natsuki Kodaka, Makoto Kuwahara, Makoto Kuwahara, Toru Tamagawa, Fumihiko Usui, Kunihito Ioka, Yi Hsi Lee, Jianyan Wei, Jinsong Deng, Weikang Zheng, Kazuo Makishima, Kazuo Makishima
Publications of the Astronomical Society of Japan   59    Oct 2007
Observations were made of the optical afterglow of GRB 051028 with the Lulin observatory 1.0 m telescope and the Wide-Field Telescope for GRB Early Timing (WIDGET) robotic telescope system. R-band photometric data were obtained on 2005 October 28 ...
Hiroki Nagakura, Kenta Hotokezaka, Yuichiro Sekiguchi, Masaru Shibata, Kunihito Ioka, Kunihito Ioka
Astrophysical Journal Letters   784    Apr 2014
The observations of jet breaks in the afterglows of short gamma-ray bursts (SGRBs) indicate that the jet has a small opening angle of ≲ 10°. The collimation mechanism of the jet is a longstanding theoretical problem. We numerically analyze the jet...
Kunihito Ioka, Kohta Murase, Kenji Toma, Shigehiro Nagataki, Takashi Nakamura
Astrophys.J.670:L77-L80,2007   670    Aug 2007
We propose an emission mechanism of prompt gamma-ray bursts (GRBs) that can
reproduce the observed non-thermal spectra with high radiative efficiencies,
>50%. Internal dissipation below a photosphere can create a radiation-dominated
thermal fireba...
Kazumi Kashiyama, Kunihito Ioka, Norita Kawanaka
Phys.Rev.D83:023002,2011   83    Sep 2010
We suggest that white dwarf (WD) pulsars can compete with neutron star (NS)
pulsars for producing the excesses of cosmic ray electrons/positrons observed
by the PAMELA, ATIC/PPB-BETS, Fermi and HESS experiments. A merger of two WDs
leads to a rapi...
Kazumi Kashiyama, Kunihito Ioka, Norita Kawanaka
Proceedings of the 20th Workshop on General Relativity and Gravitation in Japan, JGRG 2010   468-470   Dec 2010
We suggest that white dwarf pulsars can compete with neutron star pulsars for producing the excesses of cosmic ray positrons and electrons (e ± ) observed by the PAMELA, ATIC/PPB-BETS, Fermi and H.E.S.S. experiments. A double degen- erate white dw...
Kohta Murase, Kunihito Ioka
Astrophys.J. 676 (2008) 1123   676 1123-1129   Aug 2007
We present recipes to diagnose the fireball of gamma-ray bursts (GRBs) by
combining observations of electron-positron pair-signatures (the
pair-annihilation line and the cutoff energy due to the pair-creation process).
Our recipes are largely mode...
Yudai Suwa, Kunihito Ioka
Proceedings of the 20th Workshop on General Relativity and Gravitation in Japan, JGRG 2010   375-378   Dec 2010
We show that a relativistic gamma-ray burst (GRB) jet can potentially pierce the envelope of very massive first generation star (Population III; Pop III) by using the stellar density profile to estimate both the jet luminosity (via accretion) and ...
Hajime Takami, Takaya Nozawa, Kunihito Ioka, Kunihito Ioka
Astrophysical Journal Letters   789    Jul 2014
We examine dust formation in macronovae (as known as kilonovae), which are the bright ejecta of neutron star binary mergers and one of the leading sites of r-process nucleosynthesis. In light of information about the first macronova candidate asso...
Yuji Urata, Ryo Yamazaki, Takanori Sakamoto, Kuiyun Huang, Weikang Zheng, Goro Sato, Tsutomu Aoki, Jinsong Deng, Kunihito Ioka, WingHuen Ip, Koji S. Kawabata, YiHsi Lee, Xin Liping, Hiroyuki Mito, Takashi Miyata, Yoshikazu Nakada, Takashi Ohsugi, Yulei Qiu, Takao Soyano, Kenichi Tarusawa, Makoto Tashiro, Makoto Uemura, Jianyan Wei, Takuya Yamashita
Astrophysical Journal   668    Jul 2007
We study the ``normal'' decay phase of the X-ray afterglows of gamma-ray
bursts (GRBs), which follows the shallow decay phase, using the events
simultaneously observed in the R-band. The classical external shock model -- in
which neither the delay...
Hiroyuki Nakano, Kunihito Ioka
Phys.Rev.D76:084007,2007   76    Aug 2007
We formulate and calculate the second order quasi-normal modes (QNMs) of a
Schwarzschild black hole (BH). Gravitational wave (GW) from a distorted BH, so
called ringdown, is well understood as QNMs in general relativity. Since QNMs
from binary BH ...
Kunihito Ioka
Prog. Theor. Phys. 123 (2010), 743-755   123 743-755   Dec 2008
We propose that a nearby gamma-ray burst (GRB) or GRB-like (old, single and
short-lived) pulsar/supernova remnant/microquasar about 10^{5-6} years ago may
be responsible for the excesses of cosmic-ray positrons and electrons recently
observed by t...
Yudai Suwa, Yudai Suwa, Kunihito Ioka
Astrophysical Journal   726    Jan 2011
We show that a relativistic gamma-ray burst (GRB) jet can potentially pierce the envelope of a very massive first generation star (Population III, hereafter Pop III) by using the stellar density profile to estimate both the jet luminosity (via acc...
Kunihito Ioka, Hiroyuki Nakano
Phys.Rev.D76:061503,2007   76    Apr 2007
Black hole (BH) oscillations known as quasi-normal modes (QNMs) are one of
the most important gravitational wave (GW) sources. We propose that higher
perturbative order of QNMs, generated by nonlinear gravitational interaction
near the BHs, are de...

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