ROSAT Guest Observer Facility

Where can I get more information on the PSPC background?

The following papers are the best source of information:

The Particle Background of the ROSAT PSPC by Snowden, Plucinsky, Briel, Hasinger & Pfefferman (1992, ApJ, 393, 819)

A detailed description of the ROSAT PSPC particle-induced background. The PSPC rejection efficiency for these spurious events is exceptionally high with a residual count rate of roughly 5E-6 counts/sec/arcmin^2/keV. About 77 percent of events enter through the detector, while the remainder enter through the counter window. During typical conditions, the count rate of the residual counts is well correlated with the Master Veto rate. The spectrum of residual events consists of a flat component, a soft power- law, and an Al K alpha line at 1.5 keV. Typically the ratio between the power-law and flat components remains constant to +/-4 percent, while the relative Al K alpha contribution increases with increasing MV count rate. The distribution of counts over the field is uniform except for a slight radial dependance and shadowing caused by blockage of the externally produced component by the window support structure.

Updated Calibration of the ROSAT PSPC Particle Background by Plucinsky, Snowden, Hasinger, Briel, and Pfeffermann (1993, ApJ, 418, 519)

An update of the 1992 Snowden et al. paper. Includes the post gain change calibration.

Generation of Energy Dependant Exposure Maps for ROSAT PSPC Analysis by Mendenhall, Snowden, Burrows (Penn State preprint, June 1992)

The importance of energy dependant exposure maps for the analysis of ROSAT PSPC data is demonstrated. Although current SASS-generated exposure maps, based on a single, band-limited instrument map, are reasonably valid for central energies of the ROSAT bandpass, analysis of softer bands (<0.20 keV) are strongly affected by 'ghost' images. Correction for such effects is critical for studies of extended objects and the diffuse X-ray background, and may also affect the identification of soft point sources. The authors present a method of generating energy-dependant exposure maps (7 bands) for any PSPC pointed observation. These maps are based on instrument maps generated from all-sky survey data (similar to the currently used instrument map except for dividing the total PSPC bandpass into additional energy bands). Application of these maps will allow for accurate analysis over the entire PSPC bandpass.

Analysis of ROSAT XRT/PSPC Observations of Extended Objects and the Diffuse Background by Snowden, McCammon, Burrows, and Mendenhall (1994, ApJ, in press)

A "Here there be dragons" memo for those interested in reducing PSPC observations in order to study extended objects of the SXRB.

The Scattered Solar X-ray Background of the ROSAT PSPC by Snowden and Freyberg (1993, ApJ, 404, 403)

This paper models the scattered solar X-ray background as seen by the ROSAT PSPC. The temporal and geometric variation of this background component is modeled and well reproduces the observed light curves. The spectral distribution is also modeled with good results.

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This file was last modified on Friday, 27-Jul-2001 14:59:31 EDT

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