Development of Wideband X-ray Imaging Polarimeters and Hard X-ray Polarimetry

2014 Fiscal Year Final Research Report

• Project/Area Number: 23340071
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Osaka University
• Principal Investigator: HAYASHIDA Kiyoshi 大阪大学, 理学(系)研究科(研究院), 准教授 (30222227)
• Co-Investigator(Renkei-kenkyūsha): GUNJI Syuichi 山形大学, 理学部, 教授 (70241685) ; MIHARA Tatehiro 理化学研究所, 宇宙観測実験連携研究グループ, 専任研究員 (20260200) ; SAITO Yoshitaka 宇宙航空研究開発機構, 宇宙科学研究所, 准教授 (50300702)
• Project Period (FY): 2011-04-01 – 2015-03-31
• Keywords: X線偏光 / シンチレーション検出器 / 宇宙磁場 / 降着円盤 / 光電子増倍管 / 観測衛星 / PolariS

Outline of Final Research Achievements

X-ray polarimetry is effective for measuring magnetic field in super novae remnants or geometry of a accretion disk around a black hole. Nevertheless, the field has been unexploited. We are planning a small satellite, PolariS, dedicated to X-ray and gamma-ray polarimetry. We primarily developed hard X-ray imaging polarimeters for it. The polarimeter consists of scintillators and position sensitive photo multipliers. We built a such a system and improved its performance by introducing various new features in hardware and software. We obtained high positional resolution of 1.3 mm FWHM and polarization sensitivity of M of 50-60%. We also succeeded in making the lower threshold of the polarimeter down to 20keV, much lower than 50keV for previous polarimeters of similar type. The background reduction was optimized by using simulation using GEANT4 package. Overall, the polarimeters plus hard x-ray telescopes can detect hard X-ray polarization for sources with brightness of 1/100 Crab.

Free Research Field

X線天文学