The Hitomi (ASTRO-H) hard X-ray telescope (HXT): Current status of calibration

Hisamitsu Awaki, Hironori Matsumoto, Manabu Ishida, Akihiro Furuzawa, Shigeo Yamauchi, Yoshitomo Maeda, Hideyo Kunieda, Yoshito Haba, Takayuki Hayashi, Ryo Iizuka, Kazunori Ishibashi, Ikuyuki Mitsuishi, Takuya Miyazawa, Hideyuki Mori, Takashi Okajima, Satoshi Sugita, Keisuke Tamura, Yuzuru Tawara, Tessei Yoshida

Research output: Chapter in Book/Report/Conference proceedingConference contribution

4 Citations (Scopus)


The Japanese X-ray Astronomy Satellite, Hitomi (ASTRO-H) carried two hard X-ray telescopes (HXT), covering the energy band from 5 keV to 80 keV. In the initial functional verification phase of the onboard instruments, G21.5-0.9 and Crab nebula were observed with HXT. The data of G21.5-0.9 observation indicated that the hard X-ray imaging system worked well. Detail calibration of the Hitomi HXTs was performed with the observation data of Crab nebula. We extracted X-ray images of the Crab pulsar excluding the nebular emission, and confirmed that the imaging performance in orbit was satisfied with the requirement of the HXT. The 8-80 keV Crab spectrum was well fitted with a power-law model with the absorbed column of NH=3×1021 cm-2. The estimated photon index of 2.122±0.003 was consistent with previous results of Crab observation, while the observed 2-10 keV flux of 2.3×10-8 erg s-1 cm-2 was slightly larger than the previous observation. We note that there was discrepancy between the simulated and the measured effective area on ground. Thus, we introduced a fudge factor to reproduce the effective area obtained in the ground calibration. The fudge factor of HXTs are included in the latest calibration database of Hitomi.

Original languageEnglish
Title of host publicationOptics for EUV, X-Ray, and Gamma-Ray Astronomy VIII
EditorsStephen L. O'Dell, Giovanni Pareschi
ISBN (Electronic)9781510612556
Publication statusPublished - 2017
EventOptics for EUV, X-Ray, and Gamma-Ray Astronomy VIII 2017 - San Diego, United States
Duration: 08-08-201710-08-2017

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


OtherOptics for EUV, X-Ray, and Gamma-Ray Astronomy VIII 2017
Country/TerritoryUnited States
CitySan Diego

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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