Summary

This new version of ESAS is (almost) totally integrated into SAS and obeys the SAS standards. For example, the standard SAS command line flags such as -c, -h, and -V are now fully implemented for the ESAS tasks. In an effort to become more “SAS-like”, many of the routines that formerly relied on fixed file names for input/output files have been modified to allow user-specified names. Of course this requires more non-default input parameters, but will allow greater flexibility in the application of these routines. In order to help users familiar with the old ESAS convert to the new ESAS, we include a table showing the equivalencies between the old and new file names.

The mixture of base routines and scripts has engendered some confusion about what is required for XMM-ESAS to work, and what is strictly a matter of convenience. To relieve some of this confusion, some of the scripts, such as mos-filter, have been broken into more task specific pieces. The cheese task remains, but we now document how to use its components. Conversely, the mos-spectra and pn-spectra perl scripts have been completely converted to FORTRAN, mosspectra and pnspectra, and have grown in functionality. We note while these routines have, historically, been the slow choke-point for ESAS, we now have used options in the underlying backscal routines for speeding the processing. The mos_back and pn_back routines have been rewritten to become mosback and pnback, with some changes in calling and capability.

This version of ESAS introduces a new task, emanom which should, for the purposes of ESAS, replace emtaglenoise for determining whether a MOS chip is in an anomalous state.

Finally, an almost invisible change is that there is no longer a separate ESAS CCF; (almost) all ESAS calibration files are now within the standard CCF, and are called by standard SAS routines rather than fitsio routines. The remaining ESAS calibration files are now contained within the SAS distribution; we expect to eliminate/replace them in future versions.