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IX/39  The XMM-Newton 2nd Serendipitous Source Catalogue (2XMM)  (XMM-SSC, 2007)

The XMM-Newton 2nd Serendipitous Source Catalogue XMM-Newton Survey Science Centre Consortium <XMM-SSC, Leicester, UK (2007)>
ADC_Keywords: X-ray sources ; Surveys ; Mission_Name: XMM Description: 2XMM is 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. It is the largest X-ray source catalogue ever produced, containing almost twice as many discrete sources as either the ROSAT survey or pointed catalogues. The catalogue contains source detections drawn from 3491 XMM-Newton EPIC observations covering a sky area of about 360 square degrees, made between 2000 February 3 and 2007 March 31; all datasets were publicly available by 2007 May 01 but not all public observations are included in this catalogue. The catalogue contains 246897 X-ray source detections which relate to 191870 unique X-ray sources. The median flux in the total photon energy band (0.2-12keV) of the catalogue detections is about 2.5x10-14erg/cm2/s (25aW/m2). About 20% of the sources have total fluxes below 10-14erg/cm2/s (10aW/m2). The catalogue in its FITS version file ( has 246897 entries made of 297 columns; a 'slim' version gathering the 39 most relevant columns for the 191870 unique sources detected, is available as an ascii table or a FITS binary table. In both versions, the columns are fully described in the XMM-Newton User Guide available from: The original names of these columns are included in the "Byte-by-byte Description" below (uppercase names within parentheses) Details about the construction of the catalogue can be found from the XMM-Newton Survey Science Centre ( File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file xmm2slim.dat 456 191870 The 2XMM catalog, "slim" version 2880 19526 The Catalogue as a FITS binary table 2880 116014 Full XMM-Newton 2nd Serendipitous Source Catalogue (297 columns)
See also: : 2XMM Home Page B/xmm : XMM-Newton Observation Log (XMM-Newton Science Operation Center, 2002) : XMM-Newton Survey Science Centre, University of Leicester : XSA Centre at ESA's XMM-Newton SOC : XCAT-DB at SSC institute, Strasbourg : LEDAS, at the SSC institute, University of Leicester Byte-by-byte Description of file: xmm2slim.dat
Bytes Format Units Label Explanations
1- 6 I6 --- Source [1,191870] (SRCID) Unique source index 8- 11 A4 --- --- [2XMM] 13- 28 A16 --- 2XMM (IAUNAME) Unique source name 30- 37 F8.4 deg RAdeg (SC_RA) Mean source right ascension (ICRS) 39- 46 F8.4 deg DEdeg (SC_DEC) Mean source declination (ICRS) 48- 51 F4.1 arcsec ePos (SC_POSERR) Mean error on position 53- 64 E12.6 mW/m2 Flux1 (SCEP1_FLUX) Mean flux in 0.2-0.5keV band 66- 74 E9.3 mW/m2 e_Flux1 (SCEP1FLUXERR) Mean error on Flux1 76- 87 E12.6 mW/m2 Flux2 (SCEP2_FLUX) Mean flux in 0.5-1.0keV band 89- 97 E9.3 mW/m2 e_Flux2 (SCEP2FLUXERR) Mean error on Flux2 99-110 E12.6 mW/m2 Flux3 (SCEP3_FLUX) Mean flux in 1.0-2.0keV band 112-120 E9.3 mW/m2 e_Flux3 (SCEP3FLUXERR) Mean error on Flux3 122-133 E12.6 mW/m2 Flux4 (SCEP4_FLUX) Mean flux in 2.0-4.5keV band 135-143 E9.3 mW/m2 e_Flux4 (SCEP4FLUXERR) Mean error on Flux4 145-156 E12.6 mW/m2 Flux5 (SCEP5_FLUX) Mean flux in 4.5-12keV band 158-166 E9.3 mW/m2 e_Flux5 (SCEP5FLUXERR) Mean error on Flux5 168-179 E12.6 mW/m2 Flux (SCEP8_FLUX) Mean flux in 0.2-12keV band 181-189 E9.3 mW/m2 e_Flux (SCEP8FLUXERR) Mean error on Flux 191-202 E12.6 mW/m2 Flux14 ? (SCEP9_FLUX) Mean flux in 0.5-4.5keV band 204-212 E9.3 mW/m2 e_Flux14 ? (SCEP9FLUXERR) Mean error on Flux14 214-220 F7.4 --- HR1 ? (SC_HR1) Hardness ratio of bands 1 and 2 (1) 222-228 F7.4 --- e_HR1 ? (SCHR1ERR) Mean error on HR1 230-236 F7.4 --- HR2 ? (SC_HR2) Hardness ratio of bands 2 and 3 (1) 238-244 F7.4 --- e_HR2 ? (SCHR2ERR) Mean error on HR2 246-252 F7.4 --- HR3 ? (SC_HR3) Hardness ratio of bands 3 and 4 (1) 254-260 F7.4 --- e_HR3 ? (SCHR3ERR) Mean error on HR3 262-268 F7.4 --- HR4 ? (SC_HR4) Hardness ratio of bands 4 and 5 (1) 270-276 F7.4 --- e_HR4 ? (SCHR4ERR) Mean error on HR4 278-286 E9.3 --- srcML (SCDETML) Source detection likelihood (2) 288-296 E9.3 --- extML (SCEXTML) Detection likelihood of the extended source (3) 298-302 F5.3 --- Cst [0,1]? (SC_CHI2PROB) Constant probability (4) 304 I1 --- V [0,1] (SCVARFLAG) Variability flag (V=1) 306 I1 --- S [0,4] (SCSUMFLAG) summary flag (5) 308-309 I2 --- Nd (N_DETECTIONS) Number of detections 311-314 A4 --- --- [1XMM] 316-331 A16 --- 1XMM (MATCH_1XMM) Name of matched 1XMM source (6) 333-336 F4.2 arcsec o1XMM [0,3]? (SEP_1XMM) Distance of 1XMM source 338-343 I6 --- ID2XMMp ? (SRCID_2XMMP) ID of matched 2XMMp source (6) 345-349 A5 --- --- [2XMMp] 351-366 A16 --- 2XMMp (MATCH_2XMMP) Name of matched 2XMMp source (6) 368-371 F4.2 arcsec o2XMp [0,3]? (SEP_2XMMP) Distance of 2XMMp source 373-404 A32 --- --- [] 405-456 A52 --- uLEDAS (LEDAS_URL) URL for details at LEDAS
Note (1): The hardness ratio is defined as (F2-F1)/(F2+F1) if F2 is the flux in the harder band (the hardness ratio is therefore -1 for softest sources and +1 for hardest sources). The energy bands are: 1 = 0.2 - 0.5 keV (narrow band) 2 = 0.5 - 2.0 keV (narrow band) 3 = 2.0 - 4.5 keV (narrow band) 4 = 4.5 - 7.5 keV (narrow band) 5 = 7.5 - 12.0 keV (narrow band) 6 = 0.2 - 2.0 keV = soft broad band, no images made 7 = 2.0 - 12.0 keV = hard broad band, no images made 8 = 0.2 - 12.0 keV = total band 9 = 0.5 - 4.5 keV = XID band Note (2): defined as the maximum of the likelihoods of all detections of this source. Note (3): defined as the average of the extent likelihoods of all detections of this source. Note (4): χ2 probability that the unique source as detected by any of the observations is constant, that is, the minimum value of the EPIC probabilities in each detection. Note (5): The summary flag of the source is derived from the EPIC flag, and is assigned the following values: 0 = good: none of the EPIC flags was set. 1 = source parameters may be affected: at least one of the EPIC warning flags was set, but no possible-spurious detection flag is set. 2 = possibly spurious source: at least one of the possible-spurious detection flags was set but not the manual flag 3 = source located in a area where spurious detection may occur. 4 = source located in a area where spurious detection may occur and is possibly spurious. Note (6): within a radius of 3arcsec
Acknowledgements: It is a pleasure to thank Clive Page, who prepared the 'slim' version.
(End) Francois Ochsenbein [CDS] 03-Sep-2007
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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