Curriculum Vitaes
Profile Information
- Affiliation
- Professor, Graduate School of Science and Engineering, Saitama UniversitySpecially Appointed Professor, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency
- Degree
- Master (Science)(the University of Tokyo)Dr. (Science)(the University of Tokyo)
- J-GLOBAL ID
- 200901083726265608
- researchmap Member ID
- 1000161587
- External link
Research Interests
14Research History
4-
Apr, 2007 - Present
-
Sep, 2000 - Mar, 2007
-
Apr, 1993 - Aug, 2000
Education
3-
Apr, 1990 - Mar, 1993
-
Apr, 1987 - Mar, 1990
-
- Mar, 1988
Committee Memberships
2-
Nov, 2020 - Present
-
Jan, 2009 - May, 2013
Awards
2-
2007
-
1999
Papers
203-
Journal of Astronomical Telescopes, Instruments, and Systems, 4(1), Jan 1, 2018 Peer-reviewed
-
Journal of Astronomical Telescopes, Instruments, and Systems, 4(2), 2018 Peer-reviewed
-
Journal of Astronomical Telescopes, Instruments, and Systems, vol.4 011217, Jan, 2018 Peer-reviewed
-
The Astrophysical Journal, 850(2) 193-193, Dec 1, 2017 Peer-reviewed
-
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 69(3), Jun, 2017 Peer-reviewed
-
Monthly Notices of the Royal Astronomical Society, 466(4) 4558-4567, May 1, 2017
-
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 229(2), Apr, 2017 Peer-reviewed
-
JOURNAL OF LOW TEMPERATURE PHYSICS, 184(1-2) 498-504, Jul, 2016 Peer-reviewed
-
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 68, Jun, 2016 Peer-reviewedWe report on the T-90 and T-50 duration distributions and their relations with spectral hardness using 1464 gamma-ray bursts (GRBs), which were observed by the Suzaku Wide-band All-sky Monitor (WAM) from 2005 August 4 to 2010 December 29. The duration distribution is clearly bimodal in three energy ranges (50-120, 120-250, and 250-550 keV), but is unclear in the 550-5000 keV range, probably because of the limited sample size. The WAM durations decrease with energy according to a power-law index of -0.058(-0.034, +0.033). The hardness-duration relation reveals the presence of short-hard and long-soft GRBs. The short: long event ratio tends to be higher with increasing energy. We compared the WAM distribution with ones measured by eight other GRB instruments. The WAM T-90 distribution is very similar to those of INTEGRAL/SPI-ACS and Granat/PHEBUS, and least likely to match the Swift/BAT distribution. The WAM short: long event ratio (0.25:0.75) is much different from Swift/BAT (0.08:0.92), but is almost the same as CGRO/BATSE (0.25:0.75). To explain this difference for BAT, we examined three effects: BAT trigger types, energy dependence of the duration, and detection sensitivity diffe
-
Publications of the Astronomical Society of Japan, 68(SP1) S10-S10, Jun, 2016 Peer-reviewed
-
Meeting Abstracts of the Physical Society of Japan, 71 367-367, 2016
-
Review of Scientific Instruments, 87(11), 2016 Peer-reviewed
-
Meeting Abstracts of the Physical Society of Japan, 71 509-509, 2016
-
SPACE TELESCOPES AND INSTRUMENTATION 2016: ULTRAVIOLET TO GAMMA RAY, 9905, 2016
-
SPACE TELESCOPES AND INSTRUMENTATION 2016: ULTRAVIOLET TO GAMMA RAY, 9905, 2016
-
SPACE TELESCOPES AND INSTRUMENTATION 2016: ULTRAVIOLET TO GAMMA RAY, 9905, 2016 Peer-reviewed
-
SPACE TELESCOPES AND INSTRUMENTATION 2016: ULTRAVIOLET TO GAMMA RAY, 9905, 2016 Peer-reviewed
-
Astrophysical Journal, 805(2), Jun 1, 2015
-
Publications of the Astronomical Society of Japan, vol.67 46, Jun, 2015 Peer-reviewed
-
Publications of the Astronomical Society of Japan, vol.67 41, Jun, 2015 Peer-reviewed
-
Meeting Abstracts of the Physical Society of Japan, 70 471-471, 2015
-
Monthly Notices of the Royal Astronomical Society, 442(3) 2768-2779, 2014
-
SPACE TELESCOPES AND INSTRUMENTATION 2014: ULTRAVIOLET TO GAMMA RAY, 9144, 2014 Peer-reviewed
-
SPACE TELESCOPES AND INSTRUMENTATION 2014: ULTRAVIOLET TO GAMMA RAY, 9144, 2014 Peer-reviewed
-
2014 IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE (NSS/MIC), 2014 Peer-reviewed
-
SPACE TELESCOPES AND INSTRUMENTATION 2014: ULTRAVIOLET TO GAMMA RAY, 9144, 2014 Peer-reviewed
-
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 65(5), Oct, 2013
-
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 65(5), Oct, 2013 Peer-reviewed
-
Publications of the Astronomical Society of Japan, 65(4), Aug 25, 2013 Peer-reviewed
-
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 65(4) 74-1-11, Aug 25, 2013 Peer-reviewedThe Crab Nebula is one of the brightest and most stable sources in the X-ray sky. Year-scale flux variation from the object was recently revealed in the hard X-ray band by four satellites. This marked the first detection of year-scale variability from pulsar wind nebulae in the hard X-ray band. The Crab Nebula has been observed at least once a year for calibration purposes with the Suzaku Hard X-ray Detector (HXD) since its launch in 2005. In order to investigate possible spectral changes as well as flux variation, archival data of the HXD were analyzed. The flux variation reported by other instruments was confirmed in the 25-100 keV band by the HXD at a few percent level, but flux above 100 keV did not follow the trend in variation below 100 keV. The hardness ratios produced utilizing the PIN and GSO sensors installed in the HXD exhibit significant scattering, thereby indicating spectral variations in the hard X-ray band. The spectral changes were quantified by spectral fitting with a broken power-law model. The difference between the two photon indexes of the broken power-law model in harder and softer energy bands is in the range of < 2.54. Taking into account a flux variation o
-
Astrophysical Journal, Supplement Series, 207(2), Aug, 2013
-
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 207(2), Aug, 2013 Peer-reviewed
-
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 65(4), Aug, 2013 Peer-reviewed
-
EXPERIMENTAL ASTRONOMY, 34(2) 519-549, Oct, 2012
-
ASTROPHYSICAL JOURNAL, 751(2), Jun, 2012 Peer-reviewed
-
JOURNAL OF LOW TEMPERATURE PHYSICS, 167(5-6) 795-802, Jun, 2012 Peer-reviewed
-
AIP Conference Proceedings, 1427 265-266, May 10, 2012The Crab Nebula had been believed to be a stable standard candle for historical X-ray instruments for many years. Recently it was found that a hard X-ray flux (15-100 keV) of Crab Nebula fluctuated by 10 over 10 years. The origin of the long-term variation is still unclear, but the nature of the Crab Nebula is now hot topic both on science and hardware developments. The HXD onboard Suzaku has the highest sensitivity in the 10-600 keV band. Hence it is useful to search for flux variations and possible spectral changes. We performed systematic studies on Crab X-ray spectra in the 10-600 keV band w ith the HXD, by using 12 observations of Crab until 2010. In this paper, we summarized a hard X-ray study of Crab with the HXD. © 2012 American Institute of Physics.
-
ASTROPHYSICAL JOURNAL, 751(1) 35, May, 2012 Peer-reviewed
-
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 64(2), Apr, 2012 Peer-reviewed
-
ASTROPHYSICAL JOURNAL LETTERS, 748(1), Mar, 2012 Peer-reviewed
-
Publications of the Astronomical Society of Japan, 64(1), Feb 25, 2012 Peer-reviewed
-
SUZAKU 2011: EXPLORING THE X-RAY UNIVERSE: SUZAKU AND BEYOND, 1427, 2012 Peer-reviewed
-
SPACE TELESCOPES AND INSTRUMENTATION 2012: ULTRAVIOLET TO GAMMA RAY, 8443 844326-19pp, 2012
-
IEEE Nuclear Science Symposium Conference Record, 163-166, 2012 Peer-reviewed
-
SUZAKU 2011: EXPLORING THE X-RAY UNIVERSE: SUZAKU AND BEYOND, 1427, 2012 Peer-reviewed
-
SUZAKU 2011: EXPLORING THE X-RAY UNIVERSE: SUZAKU AND BEYOND, 1427, 2012 Peer-reviewed
-
DEATH OF MASSIVE STARS: SUPERNOVAE AND GAMMA-RAY BURSTS, (279) 411-412, 2012 Peer-reviewed
Misc.
289Presentations
101-
MAXI 15 Year Workshop for the Time Domain Astronomy, Dec 10, 2024 Invited
Teaching Experience
67Professional Memberships
2-
1987 - Present
-
1987 - Present
Research Projects
16-
Grants-in-Aid for Scientific Research, Japan Society for the Promotion of Science, Jul, 2020 - Mar, 2023
-
Grants-in-Aid for Scientific Research, Japan Society for the Promotion of Science, Apr, 2015 - Mar, 2018
-
Grants-in-Aid for Scientific Research, Japan Society for the Promotion of Science, Apr, 2010 - Mar, 2015
-
科学研究費助成事業, 日本学術振興会, 2008 - 2008
-
Grants-in-Aid for Scientific Research, Japan Society for the Promotion of Science, 2006 - 2008