Unraveling of radiation mechanisms of gamma-ray bursts with wide-band X and gamma-ray observations mainly focusing on X-ray observations

2016 Fiscal Year Final Research Report

• Project/Area Number: 24684015
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Partial Multi-year Fund
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Nagoya University (2013-2016); Waseda University (2012)
• Principal Investigator: Yamaoka Kazutaka 名古屋大学, 理学(系)研究科(研究院), 准教授 (00365016)
• Research Collaborator: YOSHIDA Atsumasa ; SAKAMOTO Takanori ; OHMORI Norisuke
• Project Period (FY): 2012-04-01 – 2017-03-31
• Keywords: Ｘ線ガンマ線天文学 / ガンマ線バースト / 国際宇宙ステーション / 全天Ｘ線監視装置(MAXI) / 高エネルギー電子、ガンマ線観測装置(CALET)

Outline of Final Research Achievements

In order to unravel radiation mechanisms of gamma-ray bursts (GRBs) which is one of the biggest explosion in the Universe, we carried out wide-band observations from X-rays to GeV gamma-rays focusing on X-rayu range below 10 keV with MAXI and CALET Gamma-ray Burst Monitor (CGBM) on the International Space Station (ISS) which was successfully launched in August 2015. The CGBM observed 61 GRBs so far (4 GRBs were simultaneously detected by MAXI), and searched for X-ray and gamma-ray counterpart of gravitational wave e\vents. MAXI observed 64 GRB candidates, and more than half of them are classifed to X-ray flashes (XRFs) whose radiations are dominant in X-rays. Furhtermore, we found that there were some weak events with soft X-ray spectrum and no X-ray conterparts found in the Swift follow-up observation. These events might be a new class for transient sources.

Free Research Field

X線ガンマ線天文学、宇宙線物理学、放射線検出技術