ARF correction may be incorrect for small regions
When using an input arf file and region, the input infile image should be binned at a resolution smaller than the region size. For example, if using a circle with a 1 ACIS pixel radius (0.5"), the infile image should be binned at subpixel resolution.
Using an input image with a binsize comparable to the size of the region does not provide arfcorr enough pixels to compute an accurate model of the PSF and therefore the corrections to the ARF become inaccurate.
Bugs fixed in CIAO 4.15
The following is a list of bugs that were fixed in the CIAO 4.15 software release.
Tool does not add a history entry to the header.
The tool does not add a history entry to the output file header, which means the dmhistory tool cannot be used to recall the command.