Abstract
The hard x-ray imaging spectroscopy system of "Hitomi" x-ray observatory is composed of two sets of hard x-ray imagers (HXI) coupled with hard x-ray telescopes (HXT). With a 12-m focal length, the system provides fine (10:7 half-power diameter) imaging spectroscopy covering about 5 to 80 keV. The HXI sensor consists of a camera, which is composed of four layers of Si and one layer of CdTe semiconductor imagers, and an active shield composed of nine Bi4Ge3O12 scintillators to provide low background. The two HXIs started observation on March 8 and 14, 2016 and were operational until 26 March. Using a Crab observation, 5 to 80 keV energy coverage and good detection efficiency were confirmed. The detector background level of 1 to 3 × 10-4 counts s?1 keV?1 cm?2 (in detector geometrical area) at 5 to 80 keV was achieved, by cutting the high-background time-intervals, adopting sophisticated energy-dependent imager layer selection, and baffling of the cosmic x-ray background and active-shielding. This level is among the lowest of detectors working in this energy band. By comparing the effective area and the background, it was shown that the HXI had a sensitivity that is same to that of NuSTAR for point sources and 3 to 4 times better for largely extended diffuse sources.
| Original language | English |
|---|---|
| Article number | 21410 |
| Journal | Journal of Astronomical Telescopes, Instruments, and Systems |
| Volume | 4 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - 2018 Apr 1 |
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Keywords
- astronomy.
- detectors
- gamma rays
- satellites
- x-rays
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Control and Systems Engineering
- Instrumentation
- Astronomy and Astrophysics
- Mechanical Engineering
- Space and Planetary Science
Cite this
Hard x-ray imager onboard Hitomi (ASTRO-H). / Nakazawa, Kazuhiro; Sato, Goro; Kokubun, Motohide; Enoto, Teruaki; Fukazawa, Yasushi; Hagino, Kouichi; Hayashi, Katsuhiro; Kataoka, Jun; Katsuta, Junichiro; Kobayashi, Shogo B.; Laurent, Philippe; Lebrun, Francois; Limousin, Olivier; Maier, Daniel; Makishima, Kazuo; Mizuno, Tsunefumi; Mori, Kunishiro; Nakamori, Takeshi; Nakano, Toshio; Noda, Hirofumi; Odaka, Hirokazu; Ohno, Masanori; Ohta, Masayuki; Saito, Shinya; Sato, Rie; Tajima, Hiroyasu; Takahashi, Hiromitsu; Takahashi, Tadayuki; Takeda, Shin'ichiro; Tanaka, Takaaki; Terada, Yukikatsu; Uchiyama, Hideki; Uchiyama, Asunobu; Watanabe, Shin; Yamaoka, Kazutaka; Yatsu, Yoichi; Yuasa, Takayuki.
In: Journal of Astronomical Telescopes, Instruments, and Systems, Vol. 4, No. 2, 21410, 01.04.2018.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Hard x-ray imager onboard Hitomi (ASTRO-H)
AU - Nakazawa, Kazuhiro
AU - Sato, Goro
AU - Kokubun, Motohide
AU - Enoto, Teruaki
AU - Fukazawa, Yasushi
AU - Hagino, Kouichi
AU - Hayashi, Katsuhiro
AU - Kataoka, Jun
AU - Katsuta, Junichiro
AU - Kobayashi, Shogo B.
AU - Laurent, Philippe
AU - Lebrun, Francois
AU - Limousin, Olivier
AU - Maier, Daniel
AU - Makishima, Kazuo
AU - Mizuno, Tsunefumi
AU - Mori, Kunishiro
AU - Nakamori, Takeshi
AU - Nakano, Toshio
AU - Noda, Hirofumi
AU - Odaka, Hirokazu
AU - Ohno, Masanori
AU - Ohta, Masayuki
AU - Saito, Shinya
AU - Sato, Rie
AU - Tajima, Hiroyasu
AU - Takahashi, Hiromitsu
AU - Takahashi, Tadayuki
AU - Takeda, Shin'ichiro
AU - Tanaka, Takaaki
AU - Terada, Yukikatsu
AU - Uchiyama, Hideki
AU - Uchiyama, Asunobu
AU - Watanabe, Shin
AU - Yamaoka, Kazutaka
AU - Yatsu, Yoichi
AU - Yuasa, Takayuki
PY - 2018/4/1
Y1 - 2018/4/1
N2 - The hard x-ray imaging spectroscopy system of "Hitomi" x-ray observatory is composed of two sets of hard x-ray imagers (HXI) coupled with hard x-ray telescopes (HXT). With a 12-m focal length, the system provides fine (10:7 half-power diameter) imaging spectroscopy covering about 5 to 80 keV. The HXI sensor consists of a camera, which is composed of four layers of Si and one layer of CdTe semiconductor imagers, and an active shield composed of nine Bi4Ge3O12 scintillators to provide low background. The two HXIs started observation on March 8 and 14, 2016 and were operational until 26 March. Using a Crab observation, 5 to 80 keV energy coverage and good detection efficiency were confirmed. The detector background level of 1 to 3 × 10-4 counts s?1 keV?1 cm?2 (in detector geometrical area) at 5 to 80 keV was achieved, by cutting the high-background time-intervals, adopting sophisticated energy-dependent imager layer selection, and baffling of the cosmic x-ray background and active-shielding. This level is among the lowest of detectors working in this energy band. By comparing the effective area and the background, it was shown that the HXI had a sensitivity that is same to that of NuSTAR for point sources and 3 to 4 times better for largely extended diffuse sources.
AB - The hard x-ray imaging spectroscopy system of "Hitomi" x-ray observatory is composed of two sets of hard x-ray imagers (HXI) coupled with hard x-ray telescopes (HXT). With a 12-m focal length, the system provides fine (10:7 half-power diameter) imaging spectroscopy covering about 5 to 80 keV. The HXI sensor consists of a camera, which is composed of four layers of Si and one layer of CdTe semiconductor imagers, and an active shield composed of nine Bi4Ge3O12 scintillators to provide low background. The two HXIs started observation on March 8 and 14, 2016 and were operational until 26 March. Using a Crab observation, 5 to 80 keV energy coverage and good detection efficiency were confirmed. The detector background level of 1 to 3 × 10-4 counts s?1 keV?1 cm?2 (in detector geometrical area) at 5 to 80 keV was achieved, by cutting the high-background time-intervals, adopting sophisticated energy-dependent imager layer selection, and baffling of the cosmic x-ray background and active-shielding. This level is among the lowest of detectors working in this energy band. By comparing the effective area and the background, it was shown that the HXI had a sensitivity that is same to that of NuSTAR for point sources and 3 to 4 times better for largely extended diffuse sources.
KW - astronomy.
KW - detectors
KW - gamma rays
KW - satellites
KW - x-rays
UR - http://www.scopus.com/inward/record.url?scp=85044840591&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85044840591&partnerID=8YFLogxK
U2 - 10.1117/1.JATIS.4.2.021410
DO - 10.1117/1.JATIS.4.2.021410
M3 - Article
VL - 4
JO - Journal of Astronomical Telescopes, Instruments, and Systems
JF - Journal of Astronomical Telescopes, Instruments, and Systems
SN - 2329-4124
IS - 2
M1 - 21410
ER -