XMM-Newton-NEWS

Contents:

• Version 13.5.0 of the Science Analysis System (SAS) released
• Updated EPIC Timing Mode Calibrations

Version 13.5.0 of the Science Analysis System (SAS) released

An intermediate version of SAS, v13.5.0, has been released. The main improvements of this release are related to upgrades in the calibration of the EPIC cameras:

• EPIC-MOS contamination correction
  
  Part of the temporal evolution of the soft X-ray EPIC-MOS response can be explained as due to an increasing layer of a contaminant, similar to what has been observed with the RGS detectors. Modelling of this contaminant as a pure Carbon layer has been implemented through a new calibration file, EMOS[1-2]_CONTAMINATION.CCF. The introduction of these files implies an upgrade of the redistribution, as well as a time-independent tuning of the quantum efficiency.


• EPIC-pn Timing mode energy scale refinement
  
  A new method (RDPHA) for correcting the energy scale in PN Timing Mode is offered as a non-default alternative through the parameter withrdpha in epevents (note that the parameter runepreject must also be set to 'yes' for this correction to apply). This algorithm is expected to eventually replace the current Rate-Dependent CTI (RDCTI) correction. As of SASv13.5.0, the RDCTI correction is applied by the metatasks epchain and epproc through the parameter runepfast ('yes' by default).

A problem leading to the potential appearance of outliers in RGS spectra when applying the heliocentric and/or the solar angle correction to the wavelength scale has been solved. In addition, many other less important improvements and small bug fixes have taken place.

As usual, SAS is distributed in binary form for several MacOs and Linux flavours, the latter both in 32-bit and 64-bit versions. Distribution of SAS in 32-bit binary versions for future releases is under evaluation and may be discontinued in one or two years time.

For more information and to download the software, please go to:

     http://www.cosmos.esa.int/web/xmm-newton/sas-news

Updated EPIC Timing Mode Calibrations

Two new CCF constituents were made public which have an impact on the energy scale in EPIC-pn Timing Mode exposures:

EPN_REJECT_0007.CCF implements the correction for X-ray Loading (XRL), see https://xmmweb.esac.esa.int/docs/documents/CAL-TN-0050-1-1.ps.gz

EPN_CTI_0030.CCF updates accordingly the Rate-Dependent CTI (RDCTI) correction and implements the new RDPHA method as a non-default alternative (see the previous item).

Users are referred to the following documents for full details:

• XRL: https://xmmweb.esac.esa.int/docs/documents/CAL-SRN-0302-1-5.pdf
• RDCTI: https://xmmweb.esac.esa.int/docs/documents/CAL-SRN-0304-1-1.pdf
• RDPHA: https://xmmweb.esac.esa.int/docs/documents/CAL-SRN-0306-1-1.pdf
• Expected quality of the energy reconstruction: https://xmmweb.esac.esa.int/docs/documents/CAL-TN-0083.pdf

The aforementioned changes have no effect on exposures in Burst Mode, or in imaging modes.

 

Yours sincerely,
XMM-Newton SOC