31-January-2025
Dear Colleagues,
The XMM-Newton SAS team is pleased to announce the release of a new version of the SAS:
SAS v22.0.
Main Improvements in SAS v22.0:
- MOS Effective Area Correction:
An effective area correction for the MOS cameras, intended to make MOS spectral fits compatible with EPIC-pn spectral fits(1) has been turned on by default within
arfgen via the parameter:
applyxcaladjustment = yes
This results in an increase of fluxes returned from MOS spectral fits by ~3-10%, depending on the energy band selected and the spectral shape of the source.
- Absolute Flux Correction:
The absolute flux correction has been turned on by default in
arfgen via the parameter:
applyabsfluxcorr = yes
This means that the EPIC effective areas are modified in the 3-12 keV band so that EPIC spectra match more closely spectral slopes returned by fits to NuSTAR data(2)
- RGS Effective Area Correction:
A correction for RGS effective areas (RGS rectification) is now enabled by default in
rgsrmfgen via the parameter:
withrectification = yes
This increases flux returned by RGS spectral fitting by a quantity dependent on the wavelength and on the observation date. With this correction the RGS and EPIC-pn cameras should return very similar
fluxes aiding simultaneous spectral fitting(3)
- Changes to
espfilt Filtering:
Filtering on FLAG and PATTERN has been removed from
espfilt by default. This improves the flexibility of the task but means that existing scripts which use event files produced by
espfilt will need to implement that filtering separately at a later stage.
- Improved Coordinate Accuracy:
A problem with the accuracy of coordinates towards the edge of large (>5 degree) images and exposure maps has been resolved by introducing an update to the
attcalc task
- OM Camera Response Correction:
The OM processing now applies a time-dependent, position-dependent factor to correct for degradation of the camera response over the field of view and particularly at the boresight. This needs the
new calibration file - OM_PHOTTONAT_0009.CCF and is implemented in the task
omatt, which is called by the OM chains.
- Enhanced RAW to det/sky Coordinate Conversion:
The accuracy of the conversion between RAW and det/sky coordinates has been improved in the task
ecoordconv.
- Fix for False Sources in Source Detection Chain:
A problem in the interpretation of detector mask coordinates which sometimes resulted in an excess of false sources produced by the source detection chain has been resolved. This fixes an error
introduced in eboxdetect in SAS v21.0.
Available Versions:
SAS v22.0 is released in three 64-bit Linux binary versions (Ubuntu 22.04LTS, Ubuntu 24.04LTS, and Red Hat 8.10) and
two for macOS (13.6.9 Ventura and 14.6.1 Sonoma). A Red Hat 9 version will be released shortly. Binaries for the diverse flavors of Linux and macOS are available for download from:
SAS analysis threads have been updated for compatibility with SAS v22.0 and can be accessed at:
COSMOS SAS Data Analysis Threads - XMM-Newton - Cosmos
Note for Users:
The naming convention for the SAS binary has changed. The new format is as follows:
xmmsas_22.0.0-9173c7d25-20250128
- xmmsas_22.0.0 → SAS version
- 9173c7d25 → Git commit tag for the SAS v22.0.0 release
- 20250128 → SAS build date
Best regards,
The XMM-Newton SAS Team
¹ See CAL-SRN-0382 and CAL-SRN-0410.
² See CAL-SRN-0388.
³ See CAL-SRN-401.
