XMMSSCLWBD ivo://nasa.heasarc/xmmssclwbd NASA/GSFC HEASARC Lin et al. 2026-06-05 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source The authors have carried out a classification of 4,330 X-ray sources in the 2XMMi-DR3 catalog. The sources were selected under the requirement of being a point source with multiple XMM-Newton observations and at least one detection with a signal-to-noise ratio larger than 20. For about one-third of the sources, the authors are able to obtain reliable source types from the literature. They mostly correspond to various types of stars (611), active galactic nuclei (AGNs, 753), and compact object systems (138) containing white dwarfs, neutron stars, and stellar-mass black holes. The authors find that about 99% of stars can be separated from other source types based on their low X-ray-to-IR flux ratios and frequent X-ray flares. AGNs have remarkably similar X-ray spectra, with the power-law photon index centered around 1.91 +/- 0.31, and their 0.2-4.5 keV flux long-term variation factors have a median of 1.48, with 98.5% being less than 10. In contrast, 70% of compact object systems can be very soft or hard, highly variable in X-rays, and/or have very large X-ray-to-IR flux ratios, separating them from AGNs. Using these results, the authors derive a source type classification scheme to classify the other sources and find 644 candidate stars, 1,376 candidate AGNs, and 202 candidate compact object systems, whose false identification probabilities are estimated to be about 1%, 3%, and 18%, respectively. There are still 320 sources associated with nearby galaxies and 151 in the Galactic plane, which the authors expect to be mostly compact object systems or background AGNs. There are also 100 candidate ultraluminous X-ray sources. They are found to be much less variable than other accreting compact objects. This table contains the list of 19,637 detections of the 4,330 unique X-ray sources which comprise the authors' sample. The list of 4,330 unique X-ray sources and their classifications is also available as the HEASARC XMMSSCLWBS table. This table was created by the HEASARC in October 2012 based on an electronic version of Table 3 from the reference paper which was obtained from the ApJ web site. This is a service provided by NASA HEASARC . 2012ApJ...756...27L https://heasarc.gsfc.nasa.gov/W3Browse/all/xmmssclwbd.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=xmmssclwbd& GET text/xml 180 99999 true 46.55523 -78.04514 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=xmmssclwbd GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_xmmssclwbd&Action=More+Options&Action=Parameter+Search&ConeAdd=1 XMM-NEWTON 0.0166666666666667 X-ray public xmmssclwbd XMM-Newton 2XMMi-DR3 Selected Source Detections Catalog srcid Unique Source Identifier meta.id int nullable name 2XMMi-DR3 Source Designation meta.id;meta.main char nullable ra Right Ascension degree pos.eq.ra;meta.main double nullable dec Declination degree pos.eq.dec;meta.main double nullable obsid Observation Identifier meta.id;obs char nullable m1_3_rate R3 MOS1-Medium-Filter Equivalent Count Rate in 1.0-2.0 keV ct/s phot.count;em.X-ray.soft double nullable m1_3_rate_error Error in R3 ct/s stat.error;phot.count;em.X-ray.soft double nullable m1_4_rate R4 MOS1-Medium-Filter Equivalent Count Rate in 2.0-4.5 keV ct/s phot.count;em.X-ray.medium double nullable m1_4_rate_error Error in R4 ct/s stat.error;phot.count;em.X-ray.medium double nullable m1_5_rate R5 MOS1-Medium-Filter Equivalent Count Rate in 4.5-12 keV ct/s phot.count;em.X-ray.medium double nullable m1_5_rate_error Error in R5 ct/s stat.error;phot.count;em.X-ray.medium double nullable flux PL Fit 0.2-12 keV Flux erg/s/cm^2 phot.flux;em.X-ray double nullable flux_lower Lower 90% Confidence Bound of Flux erg/s/cm^2 phot.flux;em.X-ray;stat.min double nullable flux_upper Upper 90% Confidence Bound of Flux erg/s/cm^2 phot.flux;em.X-ray;stat.max double nullable photon_index_upper Upper 90% Confidence Bound of Gamma spect.index;em.X-ray;stat.max double nullable dr3_srcid Unique Source Identifier in 2XMM-DR3 Catalog meta.id int nullable photon_index_lower Lower 90% Confidence Bound of Gamma spect.index;em.X-ray;stat.min double nullable m1_2_rate_error Error in R2 ct/s stat.error;phot.count;em.X-ray.soft double nullable m1_1_rate_error Error in R1 ct/s stat.error;phot.count;em.X-ray.soft double nullable nh_lower Lower 90% Confidence Bound of NH cm^-2 phys.columnDensity;stat.min double nullable nh Best-Fitting Column Density cm^-2 phys.columnDensity double nullable lii Galactic Longitude degree pos.galactic.lon double nullable dof Degrees of Freedom of Fit stat.fit.dof short nullable nh_upper Upper 90% Confidence Bound of NH cm^-2 phys.columnDensity;stat.max double nullable m1_2_rate R2 MOS1-Medium-Filter Equivalent Count Rate in 0.5-1.0 keV ct/s phot.count;em.X-ray.soft double nullable bii Galactic Latitude degree pos.galactic.lat double nullable m1_1_rate R1 MOS1-Medium-Filter Equivalent Count Rate in 0.2-0.5 keV ct/s phot.count;em.X-ray.soft double nullable photon_index Best-Fitting PL Photon Index spect.index;em.X-ray double nullable reduced_chi2 Reduced Chi^2 of Fit with Absorbed PL stat.fit.chi2 double nullable "__x_ra_dec" System unit vector column double nullable "__y_ra_dec" System unit vector column double nullable "__z_ra_dec" System unit vector column double nullable "__row" System index column char nullable