For a proper SAX proposal preparation the proposer should, as a minimum, execute the following operations: For a better understanding of the expected results the proposer can also simulate SAX spectral data using XSPEC.


    To estimate count rates (and exposure times for a 5 sigma detection) we provide a WWW interface, based on the HEASARC PIMMS.

    Alternatively, a command-driven version of PIMMS can be obtained from the anonymous FTP of in the software/tools directory or from the SAX-SDC anonymous FTP ( in the pub/sax/software directory.

    Click here for examples on how to use the command-driven version of PIMMS.


    The basic steps to simulate a spectrum in a SAX instrument with XSPEC are:

    Response matrices and background files are available on the following anonymous ftp accounts:

    Click here for examples on simulating spectra with XSPEC.

    Macros are available to perform simulations of NFI instruments observations using XSPEC8.50 and XSPEC9.0:

    After copying the macros the user should change: A macro can be read in XSPEC by typing at the XSPEC prompt @macro.xcm

    The macros will create the simulated spectra. Before fitting these spectra the user needs to rebin the LECS and MECS spectra to have at least 15-20 counts per channel (if he/she wants to use chi2 statistics in the fit). Rebinning can be done with the ftools GRPPHA.

    Before fitting the simulated spectra the user also needs to "ignore" :
    the first 12 channels for the LECS,
    the first 20 channels for the MECS,
    the first 20 channels for the HPGSPC

  • Please send questions/problem reports to:

    Last Revised: Jan 29th, 1996