Calibration files

The PSPC detector response matrix (DRM) and effective area files are stored in a specific calibration area which ASTERIX uses by default. The PSPC detector was changed (from detector C to B) on January 25th, 1991 and the the spectral response of the PSPC has changed in a non-linear way with time. The major effect was a large gain change on October 11th, 1991. At the present status of the calibration, it is recommended that the DRM and effective area files listed in Table 5 are used, depending on the observation date.

Table 5: Current Recommended PSPC Calibration Files

Date	PSPC	Effective Area	DRM
before Jan 25, 1991	C	pspcc_eff.sdf	drm_06.sdf
Jan 25, 1991 to Oct 11, 1991	B	pspcb_eff.sdf	drm_06.sdf
after Oct 11, 1991	B	pspcb_eff.sdf	drm_36.sdf

These files can be copied from the rosat/cal/pspc directory of the LEDAS anonymous ftp area (section 2.3) if they have not already been installed in your STARLINK node. In future versions of ASTERIX (version 1.7 and later) the software will automatically choose the correct DRM and effective area file combination for your observation.

Although the most recent version of the WFC Master Calibration File is included in the pointed observation datasets issued to PIs, it is not included in the archived datasets (as they are stored on a write-once medium). The Master Calibration File is issued as part of the ASTERIX system, but can also be copied from the rosat/cal/wfc directory of the LEDAS anonymous ftp area.