Background Subtraction

Basic background subtraction may be performed with xrtsub. This will subtract the background after normalising for area. At present the software does not perform any correction for the different detector efficiencies at the source and background box positions.

Alternatively, since most of the background is due to particles, it would also be possible simply to subtract a flat background. Software to help determine the level of this may be obtained from:

 ftp://legacy.gsfc.nasa.gov/ in directory /rosat/publications/diff_bkgrd/temp