This task creates model particle background spectra and images (if
selected with a non-zero energy range) for the selected region from
the intermediate files produced from
pnspectra. The resultant
image is in detector coordinates which is then transformed into sky
coordinates by the SAS task rotdet2sky.
pnback creates a QDP
plot file which shows the source and model background spectra for the
observation. Any enhancement of the data over the particle background
model at higher energies probably indicates residual soft proton
contamination, unless there are really hard and bright sources in the
field. This task was originally a subtask of the SAS
esas task
named
pn_back prior to SAS-21 and retains all of its
functionality.