XMM-Newton Serendipitous Source Catalogue: 2XMMp

We are pleased to announce the pre-release of the second XMM-Newton Serendipitous Source Catalogue: 2XMMp.

2XMMp is the pre-release of the second comprehensive catalogue of serendipitous X-ray sources from the European Space Agency's (ESA) XMM-Newton observatory. The catalogue has been constructed by the XMM-Newton Survey Science Centre (SSC) on behalf of ESA.

The catalogue contains source detections drawn from 2400 XMM-Newton EPIC observations made between 2000 February 4 and 2006 April 20; all datasets were publicly available by 2006 May 31 but not all public observations are included in this catalogue. The catalogue contains 153105 X-ray source detections which relate to 123170 unique X-ray sources. The median flux (in the total photon energy band 0.2 - 12 keV) of the catalogue sources is ~2.4 × 10-14 erg cm-2 s-1; ~20% have fluxes below 1 × 10-14 erg cm-2 s-1

Update: 29 August 2006

Because of an error in SQL code while creating the catalogue, the values of PN/M1/M2_CHI2PROB for observations with multiple exposures were incorrectly taken to be the largest value rather than the smallest. Despite this the VAR_FLAG values were correctly set. This affected the chi-squared probability values for 32 detections (30 unique sources) with significant variability. A table giving the old and corrected values for these is available here .

Update: 27 February 2007

The User Guide has been updated to correct a couple of mistakes and point up two new problems found (see the document revision history).


The 2XMMp catalogue, released on 2006 July 24th, is available here in FITS binary format (gzip 127 MB, MD5: 72813d0ffaee9a05dd7f96a888a577d0) , CSV format (gzip 150MB, MD5: b859ee9bd29a4f1776ff96b7aae112ab). For convenience here is a file containing a suitable SQL CREATE statement 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 following Web-based user interfaces allow filtering and searching of the catalogue, and now give links to associated data products.


The User Guide for the 2XMMp catalogue contains details of the catalogue production process and content. A description of the columns in the catalogue can be found here, and the list of observations used in the catalogue can be found here.

Nomenclature and Citation

The correct nomenclature for references to sources in the catalogue is the name starting with the '2XMMp' designator, as included in the catalogue itself, followed by a colon and the detection identification number where a specific detection is referred to (rather than the source itself), that is: "2XMMp Jhhmmss.sSddmmss:detid".

Until the catalogue paper is accepted for a refereed publication, the preferred citation of the catalogue itself is:

"The Second XMM-Newton Serendipitous Source Pre-release Catalogue,  XMM-Newton Survey Science Centre (SSC), 2006."


The production of the XMM catalogue is a collaborative project involving the whole SSC Consortium:

The SSC team is pleased to acknowledge the contributions to the SAS software, on which the catalogue processing is based, made by ESA's Science Operations Centre staff. Significant contributions to the production of the catalogue were also made by NASA Goddard Space Flight Centre HEASARC staff resident for much of the project at the University of Leicester