XMM-Newton Serendipitous Source Catalog from Stacked Observations: Obs. Data

The stacked catalog <a href="/W3Browse/xmm-newton/xmmstack.html">4XMM-DR9s</a> has been compiled from 1,329 groups, comprising 6,604 overlapping good-quality XMM-Newton observations. They were selected from the public observations taken between 2000 February 3 and 2018 November 13 which overlap by at least one arcminute in radius and are not affected by very high background emission. It contains 288,191 unique sources, 218,283 of them multiply observed, with positions and source parameters like fluxes in the XMM-Newton standard energy bands, hardness ratios, quality estimate, and information on inter-observation variability. The parameters are directly derived from the simultaneous fit, and, wherever applicable, additionally calculated for each contributing observation. The catalog aims at exploring the multiply observed sky regions and exploit their survey potential, in particular to study the long-term behavior of X-ray emitting sources. It thus makes use of the long(er) effective exposure time per sky area and offers the opportunity to investigate flux variability directly through the source detection process. The main catalog properties are summarized in the table below, the data processing and the stacked source detection are described in the processing summary. Updates compared to the previous version include a significantly larger sample of observations, event-based astrometric corrections before running source detection, revised background parameters, and manually set flags marking obviously spurious detections. This table contains the parameters of the observations at the fitted position for each stacked observation in <a href="/W3Browse/xmm-newton/xmmstack.html">the stacked catalog, 4XMM-DR9s</a>. The authors referred to the EPIC instruments with the following designations: PN, M1 (MOS1), and M2 (MOS2). The energy bands used in the 4XMM-DR9 processing were the same as for the 3XMM catalog. The following are the basic energy bands: <pre> 1: 0.2-0.5 keV 2: 0.5-1.0 keV 3: 1.0-2.0 keV 4: 2.0-4.5 keV 5: 4.5-12.0 keV </pre> All-EPIC values cover the energy range 0.2-12.0 keV. The following table gives an overview of the statistics of this catalog in comparison with the previous stacked catalog, 3XMM-DR7s: <pre> 4XMM-DR9 3XMM-DR7s Number of stacks 1329 434 Number of observations 6604 789 Time span first to last observation Feb 03, 2000 Feb 20, 2000 -- Nov 13, 2018 -- Apr 02, 2016 Approximate sky coverage (sq. deg) 485 150 Approximate multiply observed sky area(sq. deg) 300 100 Total number of sources 288191 71951 Sources with several contributing observations 218283 57665 Multiply observed sources with flag 0 or 1 191497 55450 Multiply observed and manually flagged 19224 -- Multiply observed with a total detection 181132 49935 likelihood of at least six Multiply observed with a total detection 153487 42077 likelihood of at least ten Multiply observed extended sources 9457 2648 with flag 0 or 1 Multiply observed point sources 20588 5358 with VAR_PROB <= 1% and flag 0 or 1 Multiply observed point sources 7478 1839 with VAR_PROB <= 10<sup>-5</sup> and flag 0 or 1 </pre>

Source https://heasarc.gsfc.nasa.gov/W3Browse/all/xmmstackob.html
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_datacite&identifier=ivo://nasa.heasarc/xmmstackob
Creator Traulsen et al.
Publication Year 2020
Contact Michael Preciado <Michael.E.Preciado@nasa.gov>
Resource Type AstroObjects
Format text/xml
Discipline Various