Obtain a radial profile estimating the background level from a background map.
input files: xdata$snr.qp; xdata$snr_bbk.imh
intermediate file: broad.imh
output file: broad_cnt.tab
cl> xray
xr> image
im> imcopy ``xdata$snr.qp[pi=2:10,bl=2]'' broad.imh # Selecting PI channels 2--10
# and spatial blocking factor 2
im> bye # Unload unnecessary packages
# and load the relevant ones
xr> xspatial
xs> imcnts addbkgderr=no # Do not add the background error
source image file: broad # broad.imh
source region descriptor: a 251.5 256.5 0 25 n=5
# 5 annuli at 251.5,256.5 0 to 25 pixel min/max radii
background image file or cts/pixel: xdata$snr_bbk
# Broad band background map xdata$snr_bbk.imh
bkgd region descriptor: a 251.5 256.5 0 25 n=5
# From the same region as the source counts
root name for output file [root_cnt.tab]: broad # Output file is broad_cnt.tab
Alternatively, the blocking and pi selection can be done as input to the task avoiding the creation of another data file.
input files: xdata$snr.qp; xdata$snr_bbk.imh
output file: broad_cnt.tab
xs> imcnts addbkg=no # Run the task as above
# Do not add the background error
source image file: xdata$snr[pi=2:10,bl=2]
# energy filtering and spatial blocking on the original xdata$snr.qp file
source region descriptor: a 251.5 256.5 0 25 n=5
# 5 annuli centered at 251.5,256.5, 0 to 25 pixel min/max radii
background image file or cts/pixel: xdata$snr_bbk
# Broad band background map xdata$snr_bbk.imh
bkgd region descriptor: a 251.5 256.5 0 25 n=5
# From the same region as the source counts
root name for output file [root_cnt.tab]: broad # broad_cnt.tab