Simulation Tools

The package contains response matrices and effective area files for the 3 notional X-ray Surveyor science instruments:

• High Definition X-ray Imager ("hdxi")
• The microcalorimeter spectrometer ("calorimeter")
• The CAT implementation of the X-ray grating spectrometer ("cat")

The package also contains background files for the hdxi and calorimeter instruments. To properly use the backgrounds in XSPEC simulations, they first need to be rescaled to the appropriate source extraction area. This is done with the script scale_xrs_bg also included in the package. scale_xrs_bg needs FTOOLS.

Usage:

./scale_xrs_bg xrs_hdxi_bg.pha area outputbg.pha

Where area is your source extraction area in square arcsec.

After you've created the scaled background, it can be used with XSPEC's fakeit command as:

fakeit outputbg.pha

Then proceed with the fakeit command as usual, but please make sure that you set correct exposure time for your source.

The simulated faint source spectra are likely to have few photons in some channels, which breaks the chi^2 statistics. Please either group the simulated spectra (e.g., using grppha) or use cstat / lstat statistics in XSPEC