In-Flight Calibration of Hitomi Soft X-Ray Spectrometer (3) Effective Area

Tsujimoto, Masahiro ; Okajima, Takashi ; Eckart, Megan E ; Hayashi, Takayuki ; Hoshino, Akio ; Iizuka, Ryo ; Kelley, Richard L ; Kilbourne, Caroline A ; Leutenegger, Maurice A ; Maeda, Yoshitomo(Japan Aerospace Exploration Agency, Sagamihara, Kanagawa, Japan)

关键词: CALIBRATING;    CALORIMETERS;    CONTINUUMS;    CRYOGENIC EQUIPMENT;    HIGH RESOLUTION;    INTERSTELLAR EXTINCTION;    SPECTRAL RESOLUTION;    SPECTRUM ANALYSIS;    VALVES;    X RAY SPECTROMETERS;   

RP-ID  :  GSFC-E-DAA-TN66171

学科分类：天体物理学

美国|英语

来源: NASA Technical Reports Server

【 摘 要 】

We present the result of the in-flight calibration of the effective area of the Soft X-ray Spectrometer (SXS) on board the Hitomi X-ray satellite using an observation of the Crab nebula. We corrected for 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 interstellar extinction. We evaluated the systematic uncertainty of 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 ± 0.08 × 10(exp −8) erg s(exp-1) cm(exp −2) with a 1 σ statistical uncertainty) but is softer in the power-law index (2.19 ± 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.