XMM-Newton Serendipitous Source Catalog: 5XMM-DR15 Stacked Observations Data

XMM-Newton Serendipitous Source Catalog: 5XMM-DR15 Stacked Observations Data XMMSTACKOB ivo://nasa.heasarc/xmmstackob NASA/GSFC HEASARC Traulsen et al. 2026-06-12 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source The XMMSTACKOB table contains the list of stacks that are used for the complete Fifth XMM-Newton Serendipitous Source Catalog, 5XMM-DR15, which is the fifth generation catalog of serendipitous X-ray sources from the European Space Agency's (ESA) XMM-Newton observatory, and has been created by the XMM-Newton Survey Science Center (SSC) in collaboration with the XMM-Newton Science Operations Center (SOC) on behalf of ESA. For this fifth generation of catalogs, only a stacked catalog of sources (with the individual detections and upper limits) is provided. This stacked catalog uses improved stacking methodology which allows all the individual observations to be included, contrary to stacked versions prior to 5XMM-DR15. The 5XMM-DR15 catalog contains source detections drawn from a total of 14,616 XMM-Newton EPIC observations made between 2000 January 19 and 2024 October 14; all datasets included were publicly available by 2024 October 31 but not all public observations are included in this catalog. This is due to some observations having very poor signal to noise or processing issues. The net area of the catalog fields taking account of the substantial overlaps between observations is ~1397 deg2. 5XMM-DR15 contains 818,656 unique X-ray sources and 2,578,752 X-ray detections or upper limits above the processing likelihood threshold (column STACK_DET_ML) of 6. Almost half of all sources (411,307) have more than one detection in the catalog (up to 98 repeat observations in the most extreme case). The catalog distinguishes between extended emission and point-like detections. Parameters of detections of extended sources are only reliable up to the maximum extent measure of 80 arcseconds. There are 42,669 detections of extended emission, only about half of the number in 4XMM-DR14, but twice the number of 'clean' extended sources in 4XMM-DR14. This can be understood by the improved signal to noise in 5XMM-DR15 which is a stacked catalog, which ensures that extended sources are more reliably identified. Indeed more than 60% of the extended sources in 5XMM-DR15 (25,845) are identified as clean (SUM_FLAG < 3). Due to intrinsic features of the instrumentation as well as some shortcomings of the source detection process, some detections are considered to be spurious or their parameters are considered to be unreliable. It is recommended to use a flag as filters to obtain what can be considered a 'clean' sample. There are 764,140 out of 818,656 sources that are considered to be clean (i.e., SUM_FLAG < 3). For 408,694 detections, EPIC time series and 408,901 detections, EPIC spectra were automatically extracted during processing, and a chi2-variability test was applied to the time series. This is a significant increase since 4XMM-DR14 as these products are now extracted for detections with 50 EPIC counts, whereas 100 EPIC counts were previously required. 12,330 detections in the catalog are considered variable, within the timespan of the specific observation, at a probability of 10-5 or less based on the null-hypothesis that the source is constant. Of these, 10,907 have a SUM_FLAG < 3. On the long-term, 41,187 sources have a variability of a factor five or greater. The median flux (in the total photon-energy band 0.2 - 12 keV) of the catalog detections is ~ 1.3 x 10-14 erg/cm2/s; in the soft energy band (0.2 - 2 keV) the median flux is ~ 2.9 x 10-15, and in the hard band (2 - 12 keV) it is ~7.6 x 10-15. The flux values from the three EPIC cameras are, overall, in agreement to ~10% for most energy bands. The median positional accuracy of the catalog point source detections is generally < 1.52 arcseconds (with a standard deviation of 1.41 arcseconds). To maintain similar structure as prior to the 5XMM release, the HEASARC now provides the sources-only subset of 5XMM-DR15 as <a href="/W3Browse/xmm-newton/xmmssc.html">XMMSSC</a>, which contains one row per unique source, for the 818,656 sources. This <a href="/W3Browse/xmm-newton/xmmstack.html">XMMSTACK</a> is the complete version of the catalog and has one row per source, followed by subsequent rows with information stemming from each detection or upper limit and thus has 3,397,248 rows. They both have the same number of columns (421). This table contains key details about each stack used in the construction of the XMMSTACK catalog. The energy bands used in the 5XMM-DR15 processing were the same as for the 3XMM and 4XMM catalogs. 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> while these are the broad energy bands: <pre> 6 = 0.2 - 2.0 keV soft band, no images made 7 = 2.0 - 12.0 keV hard band, no images made 8 = 0.2 - 12.0 keV total band </pre> This database table was last updated by the HEASARC in June 2026. It contains the 5XMM-DR15 observations list, released by ESA on 2026-06-09 and obtained from the XMM-Newton Survey Science Center Consortium at <a href="http://xmmssc.irap.omp.eu/Catalogue/5XMM-DR15/5XMM_DR15.html">http://xmmssc.irap.omp.eu/Catalogue/5XMM-DR15/5XMM_DR15.html</a>. It is also available as a gzipped FITS file at <a href="http://xmmssc.irap.omp.eu/Catalogue/5XMM-DR15/5xmmdr15_obslist.fits.gz">http://xmmssc.irap.omp.eu/Catalogue/5XMM-DR15/5xmmdr15_obslist.fits.gz</a>. The previous versions of the Serendipitous Source Catalog, 3XMM-DR5, 3XMM-DR6, 3XMM-DR7, 3XMM-DR8, 4XMM-DR9, 4XMM-DR10, 4XMM-DR11, 4XMM-DR12, 4XMM-DR13, and 4XMM-DR14 are also available in the same directory for comparison purposes as the files 3XMM_DR5cat_v1.0.fits.gz, 3XMM_DR6cat_v1.0.fits.gz, 3XMM_DR7cat_v1.0.fits.gz, 3XMM_DR8_cat_v1.0.fits.gz, 4XMM_DR9_cat_v1.0.fits.gz, 4XMM_DR10cat_v1.0.fits.gz, 4XMM_DR11cat_v1.0.fits.gz, 4XMM_DR12cat_v1.0.fits.gz, 4XMM_DR13cat_v1.0.fits.gz, and 4XMM_DR14cat_v1.0.fits.gz, respectively. This is a service provided by NASA HEASARC . 2020A&A...641A.137T https://heasarc.gsfc.nasa.gov/W3Browse/all/xmmstackob.html Archive Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=xmmstackob& GET text/xml 180 99999 true 193.233 -88.10127778 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=xmmstackob GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_xmmstackob&Action=More+Options&Action=Parameter+Search&ConeAdd=1 XMM-NEWTON 0.0166666666666667 X-ray public xmmstackob XMM-Newton Serendipitous Source Catalog: 5XMM-DR15 Stacked Obser stack_id Stack Identifier meta.id;src int nullable obsid Unique Identifier of the XMM-Newton Observation meta.id;obs char nullable name Target Designation of the XMM-Newton Observation meta.id;meta.main char nullable ra Right Ascension of the XMM-Newton Observation degree pos.eq.ra;meta.main double nullable dec Declination of the XMM-Newton Observation degree pos.eq.dec;meta.main double nullable "time" Date/Time of the Start of the Observation mjd time.start;obs double nullable end_time Date/Time of the End of the Contributing Observation mjd time.end;obs double nullable xmm_revolution XMM-Newton Revolution Number of the Observation meta.id short nullable pn_submode EPIC/pn Submode Used for the Observation instr.setup char nullable m1_submode EPIC/MOS1 Submode Used for the Observation instr.setup char nullable m2_submode EPIC/MOS2 Submode Used for the Observation instr.setup char nullable pn_filter EPIC/pn Filter Used for the Observation instr;instr.filter;em.X-ray char nullable m1_filter EPIC/MOS1 Filter Used for the Observation instr;instr.filter;em.X-ray.medium char nullable m2_filter EPIC/MOS2 Filter Used for the Observation instr;instr.filter;em.X-ray.soft char 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 n_exposures Number of Exposures in the Stack meta.number short nullable cc_ra_offset Catcorr Shift of the Right Ascension in the Field arcsec pos.angDistance;pos.eq.ra double nullable cc_rot_corr Catcorr Shift of the Position Angle in the Field degree pos.posAng double nullable stack_ra Reference Coordinates of the Stack: Right Ascension degree pos.eq.ra double nullable cc_pos_offset_error 1-Sigma Uncertainty in Catcorr Total Position Shift of the Field arcsec stat.error;pos.angDistance double nullable cc_dec_offset_error 1-Sigma Uncertainty in Catcorr Shift of the Declination in the Field arcsec stat.error;pos.angDistance;pos.eq.dec double nullable cc_dec_offset Catcorr Shift of the Declination in the Field arcsec pos.angDistance;pos.eq.dec double nullable n_sources_stack Number of Sources in the Stack??? FIXME meta.number short nullable stack_dec Reference Coordinates of the Stack: Declination degree pos.eq.dec double nullable cc_refcat Catcorr Reference Catalog meta.note char nullable cc_rot_corr_error 1-Sigma Uncertainty in Catcorr Shift of the Position Angle in the Field degree stat.error;pos.posAng double nullable m2_ontime Total EPIC/MOS2 Good Exposure Time s time.duration;obs.exposure double nullable m1_bkg_crarea EPIC/MOS1 Background Rate per Area ct/s/arcsec^2 instr.background double nullable pn_ontime Total EPIC/pn Good Exposure Time s time.duration;obs.exposure double nullable bii Galactic Latitude of the XMM-Newton Observation degree pos.galactic.lat double nullable cc_nmatches Catcorr Number of Usable Matches with the Reference Catalog meta.number short nullable m2_bkg_crarea EPIC/MOS2 Background Rate per Area ct/s/arcsec^2 instr.background double nullable m1_ontime Total EPIC/MOS1 Good Exposure Time s time.duration;obs.exposure double nullable area_est Approximate Sky Area Covered by the Stack degree^2 phys.angSize double nullable n_contrib_max Maximum Number of Directly Overlapping Observations in the Stack meta.number short nullable n_observations Number of Observations in the Stack meta.number;obs short nullable m2_usage_flag Flag Indicates EPIC/MOS2 Usage in Source Detection or Photometry meta.code;instr char nullable m1_usage_flag Flag Indicates EPIC/MOS1 Usage in Source Detection or Photometry meta.code;instr char nullable m2_bkg_cprob EPIC/MOS2 Cauchy Probability Derived from M2_BKG_CRAREA stat.probability double nullable cc_pos_offset Catcorr Total Position Shift of the Field arcsec pos.angDistance double nullable m1_bkg_cprob EPIC/MOS1 Cauchy Probability Derived from M1_BKG_CRAREA stat.probability double nullable pn_bkg_crarea EPIC/pn Background Rate per Area ct/s/arcsec^2 instr.background double nullable astcorr_flag Flag Indicates Observation Was Astrometrically Corrected meta.code;pos char nullable pn_bkg_cprob EPIC/pn Cauchy Probability Derived from PN_BKG_CRAREA stat.probability double nullable cc_ra_offset_error 1-Sigma Uncertainty in Catcorr Shift of the Right Ascension in the Field arcsec stat.error;pos.angDistance;pos.eq.ra double nullable pn_usage_flag Flag Indicates EPIC/pn Usage in Source Detection or Photometry meta.code;instr char nullable lii Galactic Longitude of the XMM-Newton Observation degree pos.galactic.lon double nullable