Estimating SIXA Count Rates

Source count rates in SIXA 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 SIXA rate for a source with a 5 keV thermal bremsstrahlung spectrum, interstellar absorption of $5\times10^{20}$ cm^-2, and an ASCA SIS rate of 1 c s^-1:

   *** Small PIMMS version s2.03 (XTE compatible) ***
       1994 Dec 27 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 XTE PCA  
      <--- Use 'INSTRUMENT' command to switch to another instrument
   pimms > instrument sxg sixa
   pimms > from asca sis
   pimms > model brem 5.0 5.0e20
   pimms > go 1.0
   * For thermal Bremsstrahlung model with kT=  5.0000 keV; 
     NH =  5.000E+20 and  1.000E+00 cps in ASCA SIS  
     (Model normalization =  5.374E-03) 
   * PIMMS predicts  6.618E+00 cps with SXG SIXA  
   pimms >

In Figures 59 - 67, 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.