Updated XIS Calibration around 2 keV
In the Suzaku/XIS spectra of bright sources, residuals are often seen around 2 keV, with those in XIS1 (with the back-illuminated chip) being in the opposite sense to those in the other XIS units with front-illuminated chips.
The XIS team has released a set of new quantum efficiency files, dated 20120428.
- This update modifies XAFS structures around the Si K edge and Al K edge by adopting new absorption coefficients.
- The quantum efficiency of the BI CCD changes little (left) while those of FI CCDs change significantly (middle) to solve the "Si edge" problem.
- X-ray transmission of the optical blocking filter around the Al K edge has also been updated (right).
The quantum efficiency files, ae_xiN_quanteff_20120428.fits (or later), are used by the RMF generator, xisrmfgen. To use the new calibration, install/use the latest calibration database and re-run xisrmfgen; there is no need to reprocess the event files or re-generate the ARF files.
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