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arXiv · 1801.02104

In-flight Calibration of Hitomi Soft X-ray Spectrometer (3) Effective Area

Masahiro Tsujimoto·Takashi Okajima·Megan E. Eckart·Takayuki Hayashi·Akio Hoshino·Ryo Iizuka·Richard L. Kelley·Caroline A. Kilbourne·Maurice A. Leutenegger·Yoshitomo Maeda·Hideyuki Mori·Frederick S. Porter·Kosuke Sato·Toshiki Sato·Peter J. Serlemitsos·Andrew Szymkowiak·Tahir Yaqoob
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Abstract

We present the result of the in-flight calibration of the effective area of the Soft X-ray Spectrometer (SXS) onboard the Hitomi X-ray satellite using an observation of the Crab nebula. We corrected for the artifacts when observing high count rate sources with the X-ray microcalorimeter. We then constructed a spectrum in the 0.5-20 keV band, which we modeled with a single power-law continuum attenuated by an interstellar extinction. We evaluated the systematic uncertainty upon the spectral parameters by various calibration items. In the 2-12 keV band, the SXS result is consistent with the literature values in flux (2.20 $\pm$ 0.08) $\times$10$^{-8}$ erg s$^{-1}$ cm$^{-2}$ with a 1$σ$ statistical uncertainty) but is softer in the power-law index (2.19 $\pm$ 0.11). The discrepancy is attributable to the systematic uncertainty of about $+$6/$-$7% and $+$2/$-$5% respectively for the flux and the power-law index. The softer spectrum is affected primarily by the systematic uncertainty of the Dewar gate valve transmission and the event screening.

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Masahiro Tsujimoto, Takashi Okajima, Megan E. Eckart, Takayuki Hayashi, Akio Hoshino, Ryo Iizuka, Richard L. Kelley, Caroline A. Kilbourne, Maurice A. Leutenegger, Yoshitomo Maeda, Hideyuki Mori, Frederick S. Porter, Kosuke Sato, Toshiki Sato, Peter J. Serlemitsos, Andrew Szymkowiak, Tahir Yaqoob. 2018-01-07. In-flight Calibration of Hitomi Soft X-ray Spectrometer (3) Effective Area. https://doi.org/10.1093/pasj%2Fpsy008

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