You can plot a preliminary gamma-ray spectrum with
IDL> grs_speff,index,data,ph=1
IDL> grs_speff,index,data,ph=2
In this plot the flux of each channel is calculated by dividing counts by
the full energy peak efficiency. The full energy peak efficiency at each
channel is given by dividing ``Efficiency" in grs1_40.rel and grs2_40.rel
by 1000.
NOTE: We do not plot the first 3 channels of data of GRS-PHL1 and the first
four channels of data of GRS-PHL2 because their channel widths are
not exactly determined.