The ROSAT PSPC exposure and background maps are 128128 images (60 pixels) linearly replicated to yield 512512 arrays (15 pixels). [NB: The HRI background map is also , but with 8 pixels.] The user can re-sample these maps using IRAF tasks as follows:
cl> images im> magnify rp110590_mex rp110590_mex_demag dx=4 dy=4 inter=linear # yields a # 128*128 exposure map, i.e., true resolution im> magnify rp110590_mex_demag rp110590_mex_15 4 4 inter=spline3 # yields a # 512*512 map with # 15'' pixels generated using a # 3rd order spline interpolation
The user can apply different interpolation functions to obtain the optimum result. Please note that the size of the final image may not be exactly 512*512 due to edge effects of the binning (type help magnify for more information). skypix can be used to check the sky coordinates against the original image.