Flight calibration of the Suzaku XIS using the charge injection technique
Name
Ozawa-2009-Flight calibration of the Suzaku XIS using the charge injection technique.pdf
Size
1.6 MB
Format
Adobe PDF
Checksum (MD5)
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Author(s)
Ozawa, Midori
Uchiyama, Hideki
Nakajima, Hiroshi
Mori, Hideyuki
Matsumoto, Hironori
Tsuru, Takeshi Go
Koyama, Katsuji
Uchino, Masahiro
Hayashida, Kiyoshi
Tsunemi, Hiroshi
Date Issued
July 2008
Journal
Proceedings of SPIE--the International Society for Optical Engineering
Publisher
Society of Photo-Optical Instrumentation Engineers
Citation
Ozawa, Midori et al. “Flight calibration of the Suzaku XIS using the charge injection technique.” Space Telescopes and Instrumentation 2008: Ultraviolet to Gamma Ray. Ed. Martin J. L. Turner & Kathryn A. Flanagan. Marseille, France: SPIE, 2008. 70112B-12. © 2008 SPIE
Version
Final published version
Abstract
The X-ray Imaging Spectrometer (XIS) on board the Suzaku satellite is an X-ray CCD camera system that has features of a low background, high quantum efficiency, and good energy resolution in the 0.2 - 12 keV band. Because of the radiation damage, however, the energy resolution of the XIS has been degraded since Suzaku was launched (July 2005). One of the major advantages of the XIS over the other X-ray CCDs in orbit is the provision of a precision charge injection (CI) capability. In order to improve the energy resolution, the precise measurement of charge transfer inefficiency (CTI) is essential. For this purpose, we applied the checker-flag CI, and we were able to measure the CTI of each CCD column. Furthermore, we were able to obtain the pulse height dependency of the CTI. Our precise CTI correction using these results improved the energy resolution from 193 eV to 173 eV in FWHM at 5.9 keV in July 2006 (one year after the launch). The energy resolution can be improved also by reducing the CTI. For this purpose, we applied the spaced-row charge injection (SCI); periodically injected artificial charges work as if they compensate radiation-induced traps and prevent electrons produced by X-rays from being captured by the charge traps. Using this method, the energy resolution improved from 210 eV to 150 eV at 5.9 keV in September 2006, which is close to the resolution just after the launch (145 eV). We report the current in-orbit calibration status of the XIS data using these two techniques. We present the time history of the gain and energy resolution determined from onboard calibration sources ([subscript 55]Fe) and observed calibration objects like E0102-72.
MIT Department
MIT Kavli Institute for Astrophysics and Space Research
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Persistent DSpace Link
DOI of Published Version
http://dx.doi.org/10.1117/12.788258
