The first version of epiclccorr will be optimised to correct
time series extracted from point sources. The Absolute
Correction will be finally applied to the corrected source TS
background substracted.
A coarse spectrum (50 eV bins) will be produced by evselect
from
the source region, over the energy range used in the constructions of
the TS. This will be used with arfgen
to find the effective area
array for the source as a function of photon energy.
arfgen
will be executed twice; The fist call with the spectrum
in the real position (off-axis) and with the standard default
parameters.
A second call to arfgen
using the parameters (withsourcepos=yes sourcecoords="tel" sourcex=0 sourcey=0 filterdss=no
withdetbounds=yes withbadpixcorr=N modelee=N detmaptype=flat
detxbins=1 detybins=1) will calculate the ideal effective area of
this camera/filter combination with no losses.
By dividing the effective area, returned by arfgen
for an
infinite on-axis extraction region by the effective area returned from
the actual extraction region, we will obtain an array of absolute
corrected factors (Fig.see figure:). These will be weighted by the
source spectrum to find a single absolute correction factor.
