This model is now in the Xspec release and this page is superceded by the Xspec manual
This convolution model can be used with any other combination of
models in order to estimate the photon flux and errors. The first two
parameters are the minimum and maximum energy (in keV) over which the
flux is calculated. These parameters must be frozen. The third
parameter is the photon flux in photons/cm^2/s. It is important to
ensure that the energy range over which the model is
calculated (which is determined by the response matrix in use) covers
the energy range for which the photon flux is calculated.
To use this model place the cpflux component immediately in front of
the component(s) for which you want to estimate the photon flux and fix the
normalization parameter of one of the additive
components. Now fit and use the error command as usual on the flux
parameter. For instance, suppose the model is :
phabs*(pow + gauss)
then
cpflux*phabs*(pow + gauss)
with the normalizaton of the power-law model fixed gives the photon flux and
error on the entire model.
phabs*cpflux*(pow + gauss)
again with the normalization of the power-law fixed gives the
unabsorbed photon flux and error. Finally,
phabs*(pow + cpflux*gauss)
with the normalizaton of the gaussian fixed gives the photon flux and error
on the gaussian component.
