Estimating HEPC/LEPC Count Rates

Source count rates in HEPC/LEPC can be estimated using HEASARC's multi-mission simulator PIMMS. It is assumed that a spectral model and either an absolute flux or a count rate in another instrument are known. The following dialog illustrates the use of PIMMS to estimate the HEPC/LEPC rate for a source with a 10^7.4 K Raymond-Smith spectrum, cosmic abundances, $N_H~=~3\times 10^{20}$ cm^-2, and a 0.5-2.0 keV flux, at the detector, of $9\times 10^{-14}$ erg cm^-2 s^-1.

sxg-95: pimms
*** PIMMS version 2.3 ***
    1996 Jun 03 release
    (this version does not simulate images)
    Reading mission directory, please wait
* Current model is BREMSSTRAHLUNG, kT=  10.0000 keV; NH =  1.000E+21 
   <--- Use 'MODEL' command to change
* By default, input rate is taken to be
 Flux (  2.000- 10.000 keV) in ergs/cm/cm/s 
   <--- Use 'FROM' command to change the default
* Simulation product will be
 Count rate in ASCA SIS  (  0.000-  0.000 keV)
   <--- Use 'INSTRUMENT' command to switch to another instrument
PIMMS > from flux erg 0.5-2.0
PIMMS > model rs 2.165 3.0e20    
PIMMS > instrument sxg lepc low
PIMMS > go 9.0e-14
* For Raymond Smith model with kT=  2.1645 keV (logT=7.4); NH =  3.000E+20 
   and a flux (  0.500-  2.000keV) of  9.000E-14 ergs/cm/cm/s  
  (Model normalization =  2.743E-03) 
* PIMMS predicts  3.003E-02 cps with SXG LEPC LOW 
PIMMS > instrument sxg hepc
PIMMS > go 9.0e-14
* For Raymond Smith model with kT=  2.1645 keV (logT=7.4); NH =  3.000E+20 
   and a flux (  0.500-  2.000keV) of  9.000E-14 ergs/cm/cm/s  
  (Model normalization =  2.743E-03) 
* PIMMS predicts  6.162E-03 cps with SXG HEPC  
PIMMS > quit
sxg-96:

In Figures  - 32, we provide count rate conversion factors from ASCA and ROSAT rates, for power law, bremsstrahlung, and black body spectra, and a range of spectral parameters.

PIMMS may be obtained from the software/tools directory in the anonymous ftp node legacy.gsfc.nasa.gov. Version 2.0 includes support for SXG instruments. To update earlier versions, users may obtain new mission lists and SXG area files from the directory /pub/sxg/pimms in the anonymous ftp node sao-ftp.harvard.edu.