A three-segment broken power law (i.e. with two break energies).
where:
par1 = ![]() |
power law photon index for
![]() |
par2 = ![]() |
first break point for the energy in keV |
par3 = ![]() |
power law photon index for
![]() |
par4 = ![]() |
second break point for the energy in keV |
par5 = ![]() |
power law photon index for
![]() |
norm = K | photons/keV/cm![]() |
If POW_EMIN and POW_EMAX have been defined by the xset command then
the norm becomes the flux in units of ergs/cm
/s over the
energy range (POW_EMIN, POW_EMAX) keV unless POW_EMIN = POW_EMAX in
which case the norm becomes the flux density in micro-Jansky at
POW_EMIN keV. In these cases it is important that POW_EMIN and
POW_EMAX lie within the energy range on which the model is being
evaluated.