The XMM-Newton Survey Science Centre is pleased to announce a further incremental version of the Second XMM-Newton Serendipitous Source Catalogue, 2XMMi-DR3.
The 2XMMi-DR3 catalogue is the fifth publicly released XMM X-ray source catalogue produced by the XMM Survey Science Centre (SSC) consortium on behalf of ESA. It follows the 1XMM (released in April 2003), 2XMMp (July 2006), 2XMM (August 2007) and 2XMMi (August 2008) catalogues: 2XMMp was a preliminary version of 2XMM. 2XMMi and 2XMMi-DR3 are incremental versions of the 2XMM catalogue.
With this increment catalogue, for the first time, as part of the catalogue naming convention we introduce the concept of a data release (DR) as a means of distinguishing between increments. This is being applied only to the 2XMM generation of catalogues. In this scheme (see following table), 2XMM is considered as DR1, 2XMMi as DR2 and the present catalogue as DR3.
|Catalogue name||DR version||Full catalogue designation||Year released|
The 2XMMi-DR3 catalogue has about 22% new detections as compared to the 2XMMi catalogue and is the largest X-ray source catalogue ever produced, containing ~ 3 times as many discrete sources as either the ROSAT survey or pointed catalogues. 2XMMi-DR3 complements deeper Chandra and XMM-Newton small area surveys, probing a much larger sky area.
The catalogue provides an effective dataset for generating large, well-defined samples of various types of astrophysical object, notably active galaxies (AGN), clusters of galaxies, interacting compact binaries and active stellar coronae, using the power of X-ray selection. The large sky area covered by the serendipitous survey also means that 2XMMi-DR3 is a rich resource for exploring the variety of the X-ray source populations and identifying rare source types.
The catalogue contains source detections drawn from 4953 XMM-Newton EPIC observations made between 2000 February 3 and 2009 October 8; all datasets were publicly available by 2009 October 31 but not all public observations are included in this catalogue. The catalogue contains 353191 X-ray source detections which relate to 262902 unique X-ray sources (covering an energy interval from 0.2 keV to 12 keV). About a third of the observations have features that may cause spurious detections (mainly the wings of bright sources and large extended emission), and it is strongly recommended to use a filter (either per source or per observation). In around 62% of observations, a detection could be identified as the intended target of the observation. The following table gives an overview of the statistics of the catalogue in comparison with the 2XMMi catalogue which was published in August 2008 and also 2XMM, relased in August 2007. The increment column is with respect to 2XMMi
|Number of observations||4953||4117||3491||836|
|Number of 'clean' observations (i.e., observation class < 3)||2789||2021||1754||768|
|Observing time||03-Feb-00 -- 08-Oct-09||03-Feb-00 -- 28-Mar-08||03-Feb-00 -- 31-Mar-07||1.5 years|
|Sky coverage, taking overlaps into account||504 sq.deg||420 sq.deg||360 sq.deg||84 sq.deg|
|Number of detections||353191||289083||246897||64108|
|Number of unique sources||262902||221012||191870||41890|
|Number of extended detections||30470||24533||20837||5937|
|Number of detections with time series and spectra||56017||44621||38320||11396|
|Number of variable detections||3177||2608||2307||569|
|Number of 'clean' detections (i.e., summary flag < 3)||284270||233698||199371||50572|
The median flux in the total photon energy band (0.2 - 12 keV) of the catalogue detections is ~ 2.5 × 10-14 erg cm-2 s-1; in the soft energy band (0.2 - 2 keV) the median flux is ~ 5.6 × 10-15, and in the hard band (2 - 12 keV) it is ~ 1.4 × 10-14. About 20% of the sources have total fluxes below 1 × 10-14 erg cm-2 s-1.
The 2XMMi-DR3 catalogue, released on 2010 April 28th, is available in several formats:
|2XMMi-DR3cat_v1.0.fits.gz||FITS binary||279 MB||MD5: 9f9afe43c7728d91fe17a9aa2281709d||full binary catalogue; recommended for the experienced user and in-depth studies|
|2XMMi-DR3cat_v1.0.csv.gz||CSV||366 MB||MD5: c9c10aabc0f4f682b2965d9a74907edb||full ascii catalogue|
|2XMMi-DR3cat_slim_v1.0.fits.gz||FITS binary||32 MB||MD5: 6aeebb99f2958f4479c3ad9db411e157||reduced binary catalogue, recommended for X-ray beginners and simple studies|
|2XMMi-DR3cat_slim_v1.0.csv.gz||CSV||40 MB||MD5: 8d35de42fde34299f8779090e252a656||reduced ascii catalogue|
For convenience, there are suitable SQL CREATE statements available for use with a relational DBMS in order to load the data in CSV format:
The CSV file has nulls represented by two successive commas, compatible with Postgres and (probably) other DBMS.
The slimline version of the catalogue contains one row per unique source (while the the main catalogue has one row per detection) and thus has 262902 rows. There are 38 columns, essentially those containing information about the unique sources. The catalogue also contains a column with links to the LEDAS summary pages. In the case of sources with multiple detections the summary page of the best detection is selected (i.e., the detection with the largest exposure time, summed over all cameras), and the summary page gives cross-links to the other detections.
Two separate files are also provided (table below) which contain key details about the observations used in the construction of the 2XMMi-DR3 catalogue and information about the targets of the observations. See the list of observations and the list of target identifications for descriptions of the columns in each file.
|2XMMi-DR3_summary.fits||FITS binary||0.5 MB||MD5: 603f23573f474ca207b6b67755d78952||Summary table of observations used in the catalogue|
|2XMMi-DR3_targets.fits||FITS binary||0.8 MB||MD5: 1c2bed03606fe87526b5a4c6aaa26537||Summary table of the targets of observations used in the catalogue|
The following Web-based user interfaces will allow filtering and searching of the catalogue (and give access to all or selected associated data products):
The SSC Catalogue Home Page (this page), XSA, and HEASARC allow download of the catalogue file in (binary) FITS.
The User Guide for the 2XMMi-DR3 catalogue contains details of the catalogue production process and content. Here are quick links to
Sources that originated in the 2XMM catalogue or were new in the 2XMMi catalogue will retain their IAU name nomenclature in 2XMMi-DR3, i.e. their IAU names start with a '2XMM' or '2XMMi' designator, respectively. Sources appearing for the first time in 2XMMi-DR3 are assigned an IAU name also starting with a '2XMMi' designator. The IAU name is provided in the catalogue. The correct, full nomenclature for a specific detection from these catalogues is the IAU name, followed by a colon and the detection identification number, that is:"2XMM Jhhmmss.sSddmmss:detid" or "2XMMi Jhhmmss.sSddmmss:detid".
The production and content of the 2XMM catalogue is described in detail in "The XMM-Newton serendipitous survey. V. The second XMM-Newton serendipitous source catalogue", M. G. Watson et al., A&A 493, p. 339. Note that there are no significant differences in the processing between the 2XMM, 2XMMi and 2XMMi-DR3 observations
The production of the 2XMMi-DR3 catalogue is a collaborative project involving the whole SSC Consortium:
The SSC acknowledges the use of the TOPCAT and STILTS software packages (written by Mark Taylor, University of Bristol) in the production and testing of the 2XMMi-DR3 catalogue.