Bugs: calc_energy_flux

Bugs

1. Flux density at a single energy bin should be divided by the bin width.

Bugs

1. Flux density at a single energy bin should be divided by the bin width.

   The following command does not return the flux density at 1 keV, but the flux over [1., ~12.] keV.

   sherpa> calc_energy_flux(1.)
           1.4245010557307638e-08
   

   This is equivalent to the following:

   sherpa> calc_energy_flux(lo=1., hi=None)
           1.4245010557307638e-08
   

   In this example, Sherpa assumes that the lower bound is 1.0 keV and the upper bound is the maximum of the energy grid, ~12.0 keV.

   sherpa> show_filter()
   
   Data Set Filter: 1
   0.1248-12.4100 Energy (keV)
   

   Workaround:

   To calculate the flux density at 1 keV in ergs/cm²/s/keV, use the following syntax:

   sherpa> lo, hi = get_arf().energ_lo, get_arf().energ_hi
   sherpa> bin_width = hi[lo==1.0]-lo[lo==1.0]
   sherpa> calc_energy_flux(1.,1.)/bin_width[0]
            1.2423851278555414e-10