README

This package contains python code for computing aperture photometry for
unresolved sources in astronomical x-ray images, as described in the article
"DETERMINING X-RAY SOURCE INTENSITY AND CONFIDENCE BOUNDS IN CROWDED FIELDS",
Primini, F.A and Kashyap, V.L. 2014, The Astrophysical Journal, v. 796, pp. 24-37.

The code is designed to run within the CIAO data analysis environment
(http://cxc.cfa.harvard.edu/ciao).


xap.py						       Main Python program
xap_funs.py					       Function and Class definitions for xap.py
xap.par						       CIAO style parameter file for xap.py
	

XAP/Example:					       Test data for Figure 1 in Primini & Kashyap, 2014
acisf01575_001N001_evt3.fits.gz			       Test Chandra Level 3 Event List
acisf01575_001N001_r0115b_psf3.fits.gz		       Level 3 PSF image for source r0115 
acisf01575_001N001_r0115b_regexp3.fits.gz	       Level 3 expmap for r0115
acisf01575_001N001_r0115_srcreg3.fits		       Level 3 source region for r0115
acisf01575_001N001_r0116b_psf3.fits.gz		       PSF image for r0116
acisf01575_001N001_r0116b_regexp3.fits.gz	       expmap for r0116
acisf01575_001N001_r0116_srcreg3.fits		       source region for r0116
acisf01575_001N001_r0123b_psf3.fits.gz		       PSF image for r0123
acisf01575_001N001_r0123b_regexp3.fits.gz	       expmap for r0123
acisf01575_001N001_r0123_srcreg3.fits		       source region for r0123
acisf01575_001N001_r0150b_psf3.fits.gz		       PSF image for r0150
acisf01575_001N001_r0150b_regexp3.fits.gz	       expmap for r0150
acisf01575_001N001_r0150_srcreg3.fits		       source region for r0150
new_acisf01575_001N001_r0116_bkgreg3.fits	       background region for all sources
r0115_r0116_r0123_r0150_psfs.lis		       stack of psf filenames
r0115_r0116_r0123_r0150_regexps.lis		       stack of expmap filenames
r0115_r0116_r0123_r0150_srcs.lis		       stack of source region filenames
mpdf_r0115_r0116_r0123_r0150_uninformative.fits	       fits file containing marginalized posterior probability
						       distributions for all sources and background, in
						       separate fits extensions 
full_dataset_uninformative_priors_27_Mar_2018.log      log of test run