XMM-NEWTON DATA ANALYSIS
SAS - The XMM-Newton Science Analysis System
The basic reduction of XMM-Newton data is provided by the Science Analysis System (SAS) software package integrated and maintained at the Science Operations Center (SOC) (see the general SOC analysis portal for specific links).
The SAS provides tasks to produce calibrated photon event files from the Observation Data Format (ODF) files supplied to the user as well as some basic analysis tools. These include data filtering and extraction, production of rmfs and arfs for spectral analysis, and source detection routines.
You can download the SAS installation file either from the SOC or the GOF's US mirror site. You should refer to both the detailed installation instructions, and the list of required helper applications that also must be installed. A current set of the calibration files require a separate installation.
XMM-Newton Analysis Within The Hera Environment
The HEASARC Hera facility provides a way to run up to date SAS tasks without locally installing XMM-Newton software or calibration files. Eventually all SAS tasks will be supported under HERA, though basic analysis tasks can be achieved now. There is a basic script for an end to end production of files for spectral analysis using the command line "runtask" form of Hera, where data inputs and products are stored locally on the user's machine.
Post SAS data analysis
The SAS was not designed for high level scientific analysis such as spectral fitting and temporal analysis. However, the SAS product files are designed to OGIP standards, so theoretically any high-level analysis package for use in high-energy astrophysics is capable of processing XMM-Newton data. For example:
- HEASoft
from the High Energy Astrophysics Science Archive Research Center (HEASARC).
- CIAO from the Chandra X-ray Observatory Center (CXC).
can both be used for XMM-Newton data analysis.
- HEASoft
from the High Energy Astrophysics Science Archive Research Center (HEASARC).
Documentation
- The XMM-Newton Users Handbook can be found on-line at
GSFC or the
SOC.
G'zipped PostScript
(8.8 Mbyte compressed, 98 Mbyte uncompressed) and
PDF
(9.4 Mbyte) versions are available.
- The SAS Users Guide can be found on-line at
GSFC or the
SOC.
G'zipped PostScript
(9 Mb) and
PDF
(4.5 Mb) versions are available. On-line documentation for the SAS
tasks can be found at
GSFC or the
SOC.
- The XMM-Newton ABC Guide for XMM data analysis, prepared by the
NASA/GSFC XMM-Newton GOF, is a companion document for the SAS.
It provides
simple analysis walk throughs and practical information.
- The XMM-Newton D Guide is an
even briefer
document, also produced by the GOF.
When the ABC Guide is too much information this
quick reference guide and memory aid for the basic SAS tasks is the alternative.
- The XMM-Newton Calibration and Background Treatment portal is here, and the topic is also discussed here at the GOF.
- The XMM-Newton Users Handbook can be found on-line at
GSFC or the
SOC.
G'zipped PostScript
(8.8 Mbyte compressed, 98 Mbyte uncompressed) and
PDF
(9.4 Mbyte) versions are available.
Other Specialized Software Tools
Here are a few important tools currently outside the SAS proper:- The XMM-ESAS Extend Source Background Modeling Software package
(available from the
GOF or
SOC)
allows the
user to create EPIC MOS background spectra and images for user-defined
regions of the detectors. While the software is currently only
implimented for the MOS detectors, work is underway to adapt the
methods to the PN.
- An Optical Monitor Script to simplify the task of getting OM
data into an easy to use format.
The code works on the Pipeline product files and produces one image
file for each filter and each low- or high-resolution mode. In
addition, it reads the exposure maps associated with the files and
produces one exposure map for each filter and each mode.
The script, and further information can be retrieved here:
ftp://legacy.gsfc.nasa.gov/xmm/software/om_tools/.
- Gnupg (GPG) for archive file decryption. In order to decrypt propriatry XMM-Newton data pgp or gpg with IDEA support is needed. If you don't already have this on your system we have made some static binaries available that will work with our decrypt script.
- The XMM-ESAS Extend Source Background Modeling Software package
(available from the
GOF or
SOC)
allows the
user to create EPIC MOS background spectra and images for user-defined
regions of the detectors. While the software is currently only
implimented for the MOS detectors, work is underway to adapt the
methods to the PN.
XMM-Newton Source Naming Convention
The XMM-Newton Observatory catalogues tens of X-ray sources and additional Optical/UV targets for each and every observation. When referring to sources in XMM observations it is appropriate to use their catalogue designation. For X-ray sources that have no designation that need to be referred to in a paper, you should use the naming convention XMMU JHHMMSS.s+/-DDMMSS,
e.g. source position: RA 03 10 15.1, Dec -76 51 31.2 (J2000) recommended acronym: XMMU J031015.1-765131
source position: RA 17 23 48.7, Dec +82 17 33.8 (J2000) recommended acronym: XMMU J172348.7+821733.
Note that position designations are truncated and not rounded. Uncatalogued optical/UV sources detected only with the Optical Monitor should be designated using the form XMMOM JHHMMSS.S+/-DDMMSS. (This is still in the process of registration with the IAU).(Based on the clairification in XMM-NEWTON NEWS #4 and private communication from Martin Still).
Other Publication Guidelines
When publishing a paper using XMM-Newton data please include the following text, preferably as a footnote to the title:"Based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA"
Each publication using XMM-Newton data should include the Target Name, the Date of the Observation and the Obs-Id to ensure that the data can be uniquely identified.
(From the SOC Publication Guidelines page.)
If you have any questions concerning XMM-Newton send e-mail to xmmhelp@lists.nasa.gov