In-flight calibration of Hitomi Soft X-ray Spectrometer. (1) Background
Abstract
The X-Ray Spectrometer (XRS) instrument of Suzaku provided the first measurement of the non-X-ray background (NXB) of an X-ray calorimeter spectrometer, but the data set was limited. The Soft X-ray Spectrometer (SXS) instrument of Hitomi was able to provide a more detailed picture of X-ray calorimeter background, with more than 360 ks of data while pointed at the Earth, and a comparable amount of blank-sky data. These data are important not only for analyzing SXS science data, but also for categorizing the contributions to the NXB in X-ray calorimeters as a class. In this paper, we present the contributions to the SXS NXB, the types and effectiveness of the screening, the interaction of the screening with the broad-band redistribution, and the residual background spectrum as a function of magnetic cut-off rigidity. The orbit-averaged SXS NXB in the range 0.3-12 keV was 4 × 10-2 counts s-1 cm-2. This very low background in combination with groundbreaking spectral resolution gave SXS unprecedented sensitivity to weak spectral lines.
- Publication:
-
Publications of the Astronomical Society of Japan
- Pub Date:
- March 2018
- DOI:
- 10.1093/pasj/psx139
- Bibcode:
- 2018PASJ...70...18K
- Keywords:
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- instrumentation: spectrographs;
- methods: observational;
- space vehicles: instruments