XMMOBSTARS ivo://nasa.heasarc/xmmobstars NASA/GSFC HEASARC Naze 2026-10-09 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Star Following the advent of increasingly sensitive X-ray observatories, deep observations of early-type stars became possible. However, the results for only a few objects or clusters have until now been reported and there has been no large survey comparable to that based upon the ROSAT All-Sky Survey (RASS). A limited survey of X-ray sources, consisting of all public XMM observations (2XMMi) and slew survey data (XMMSL1), is now available. The X-ray counterparts to hot, massive stars have been searched for in these catalogs. About 300 OB stars were detected with XMM. Half of them were bright enough for a spectral analysis to be possible, and we make available the detailed spectral properties that were derived. The X-ray spectra of O stars are represented well by low (&lt; 1 keV) temperature components and seem to indicate that an absorption column is present in addition to the interstellar contribution. The X-ray fluxes are well correlated with the bolometric fluxes, with a scatter comparable to that of the RASS studies and thus larger than found previously with XMM for some individual clusters. These results contrast with those of B stars that exhibit a large scatter in the L&lt;sub&gt;X&lt;/sub&gt; - L&lt;sub&gt;bol&lt;/sub&gt; relation, no additional absorption being found, and the fits indicate a plasma at higher temperatures. Variability (either within one exposure or between multiple exposures) was also investigated whenever possible: short-term variations are far more rare than long-term ones (the former affects a few percent of the sample, while the latter concerns between one third and two thirds of the sources). This is a catalog of X-ray emitters amongst early-type stars following a correlation between the Reed (2003, AJ, 125, 2531) Catalog of galactic OB Stars and the 2XMMi Catalog (Watson et al. 2009, A&amp;A, 493, 339). See the reference paper for more details. This table was created by the HEASARC in November 2009 based on CDS table J/A+A/506/1055 file table1.dat. This is a service provided by NASA HEASARC . 2009A&amp;A...506.1055N https://heasarc.gsfc.nasa.gov/W3Browse/all/xmmobstars.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=xmmobstars& GET text/xml 180 99999 true 82.814583333333 -71.069166666667 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=xmmobstars GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_xmmobstars&Action=More+Options&Action=Parameter+Search&ConeAdd=1 STAR CATALOG 0.0166666666666667 Optical X-ray public xmmobstars XMM-Newton OB Stars Catalog name 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 spect_type MK Spectral Type src.spType char nullable vmag V Magnitude mag phot.mag;em.opt.V double nullable xmm_name IAU-Style Designation of the 2XMM(i) Source meta.id.assoc char nullable flux Unabsorbed X-Ray Flux in 0.5-10.keV erg/s/cm^2 phot.flux;em.X-ray double nullable log_lx_lbol Logarithm of Luminosity Ratio, Log(L_X/L_BOL) phys.luminosity;arith.ratio double nullable m2_hr2_error Error on MOS2 HR2 stat.error;phot.count;arith.ratio;em.X-ray double nullable pn_hr4_error Error on pn HR4 stat.error;phot.count;arith.ratio;em.X-ray double nullable m2_filter Filter Used for EPIC-MOS2 instr;instr.filter char nullable n_detections Number of Individual Detections meta.number short nullable pn_hr3 HR3 for EPIC-pn phot.count;arith.ratio;em.X-ray double nullable component_id Flag [a-e] Indicates Identification of the Same Members of a Pair meta.code.multip char nullable pn_hr3_error Error on pn HR3 stat.error;phot.count;arith.ratio;em.X-ray double nullable pn_xid_rate Count Rate in 0.5-4.5keV for pn ct/s phot.count;em.X-ray double nullable spect_type_flag Flag [S] Indicates Spectral Type Is Uncertain meta.code;src.spType char nullable source_flag Flag [1-6] Indicates Type of Star meta.code;src.class char nullable reed_id_number Identification Number in Reed Catalog (<V/125>) meta.id.cross int nullable pn_hr4 HR4 for EPIC-pn phot.count;arith.ratio;em.X-ray double nullable m2_hr3_error Error on MOS2 HR3 stat.error;phot.count;arith.ratio;em.X-ray double nullable m1_hr4_error Error on MOS1 HR4 stat.error;phot.count;arith.ratio;em.X-ray double nullable m1_hr4 HR4 for EPIC-MOS1 phot.count;arith.ratio;em.X-ray double nullable quality_flag Overall Quality Flag (0=Best; 1-4=Possibly Spurious) meta.code.qual short nullable m2_xid_rate Count Rate in 0.5-4.5keV for MOS2 ct/s phot.count;em.X-ray double nullable class Browse Object Classification src.class short nullable nh Interstellar Absorption Column Density cm^-2 phys.columnDensity double nullable pn_filter Filter Used for EPIC-pn instr;instr.filter char nullable detection_likelihood Total Detection Likelihood stat.likelihood double nullable m1_hr2 HR2 for EPIC-MOS1 phot.count;arith.ratio;em.X-ray double nullable m2_hr4 HR4 for EPIC-MOS2 phot.count;arith.ratio;em.X-ray double nullable m1_xid_rate_error Error on the MOS1 Count Rate ct/s stat.error;phot.count;em.X-ray double nullable lii Galactic Longitude degree pos.galactic.lon double nullable m2_hr1 HR1 for EPIC-MOS2 phot.count;arith.ratio;em.X-ray double nullable binary_flag Flag [Y] Indicates Binary System meta.code.multip char nullable pn_hr1_error Error on pn HR1 stat.error;phot.count;arith.ratio;em.X-ray double nullable m1_hr1 HR1 for EPIC-MOS1 phot.count;arith.ratio;em.X-ray double nullable pn_hr1 HR1 for EPIC-pn phot.count;arith.ratio;em.X-ray double nullable pn_hr2 HR2 for EPIC-pn phot.count;arith.ratio;em.X-ray double nullable m1_hr1_error Error on MOS1 HR1 stat.error;phot.count;arith.ratio;em.X-ray double nullable m1_hr3_error Error on MOS1 HR3 stat.error;phot.count;arith.ratio;em.X-ray double nullable bii Galactic Latitude degree pos.galactic.lat double nullable ltv_flag Long-Term Variability Flag [0-2] meta.code;src.var short nullable m1_filter Filter Used for EPIC-MOS1 instr;instr.filter char nullable m2_hr2 HR2 for EPIC-MOS2 phot.count;arith.ratio;em.X-ray double nullable pn_xid_rate_error Error on the pn Count Rate ct/s stat.error;phot.count;em.X-ray double nullable m2_hr3 HR3 for EPIC-MOS2 phot.count;arith.ratio;em.X-ray double nullable photometry_flag Flag [S] indicates Photometry Taken from SIMBAD meta.code;phot.mag char nullable pn_hr2_error Error on pn HR2 stat.error;phot.count;arith.ratio;em.X-ray double nullable m1_hr2_error Error on MOS1 HR2 stat.error;phot.count;arith.ratio;em.X-ray double nullable m2_xid_rate_error Error on the MOS2 Count Rate ct/s stat.error;phot.count;em.X-ray double nullable alt_name Alternative 2XMMi Catalog Source Designation meta.id char nullable m2_hr4_error Error on MOS2 HR4 stat.error;phot.count;arith.ratio;em.X-ray double nullable m1_xid_rate Count Rate in 0.5-4.5keV for MOS1 ct/s phot.count;em.X-ray double nullable stv_flag Short-Term Variability Flag [1=Variable] meta.code;src.var short nullable m2_hr1_error Error on MOS2 HR1 stat.error;phot.count;arith.ratio;em.X-ray double nullable log_fbol Logarithm of the Bolometric Flux log(erg/s/cm^2) phot.flux.bol double nullable m1_hr3 HR3 for EPIC-MOS1 phot.count;arith.ratio;em.X-ray double nullable bv_color B-V Color Index mag phot.color;em.opt.B;em.opt.V 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 off_set Distance between X-Ray Source and Star (arcsec) arcsec pos.angDistance double nullable