J/ApJ/643/356ivo://CDS.VizieR/J/ApJ/643/356doi:10.26093/cds/vizier.16430356CDSWilliams B.F.Naik S.Garcia M.R.Callanan P.J.2017-09-29T09:04:04Z2008-12-26T22:38:31ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frgalaxiesx-ray-sourcesFrom 1999 October to 2002 August, 45 transient X-ray sources were detected in M31 by Chandra and XMM-Newton. We have performed spectral analysis of all XMM-Newton and Chandra ACIS detections of these sources, as well as flux measurements of Chandra HRC detections. The result is absorption-corrected X-ray light curves for these sources covering this 2.8yr period, along with spectral parameters for several epochs of the outbursts of most of the transient sources. We supply a catalog of the locations, outburst dates, peak observed luminosities, decay time estimates, and spectral properties of the transient sources, and we discuss similarities with Galactic X-ray novae. Duty cycle estimates are possible for eight of the transients and range from 34% to 2%; upper limits to the duty cycles are estimated for an additional 15 transients and cover a similar range. We find five transients that have rapid decay times and may be ultracompact X-ray binaries. Spectra of three of the transients suggest that they may be faint Galactic foreground sources. If even one is a foreground source, this suggests a surface density of faint transient X-ray sources of >~1deg^2^.2006ApJ...643..356Whttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/643/356CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/chandra : The Chandra Archive Log (CXC, 2002)J/ApJ/577/738 : M31 Chandra X-ray point sources (Kong+, 2002)J/ApJ/578/114 : Chandra HRC source in M31 (Kaaret, 2002)J/ApJ/609/735 : M31 Chandra X-ray sources (Williams+, 2004)J/ApJ/610/247 : M31 supersoft and quasi-soft X-ray sources (Di Stefano+, 2004)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/643/356https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/643/356http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/643/356https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/643/356https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/643/356http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/643/356GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/643/356/table1 (Transient catalog)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/643/356/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/643/356/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/643/356/table1?GETtext/xml+votable180.050000true11.662541.65208330.0055555555555555566/2622 2623 2666 2705 2708 2709 2752https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/643/356?format=asciiX-raydefaultJ/ApJ/643/356/table1Transient catalogrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint[KGP2002]Source identification (origin in Kong et al. 2002ApJ...577..738K, Cat. J/ApJ/577/738)meta.id;meta.maincharprimaryRAJ2000Riight ascension (J2000.0)pos.eq.ra;meta.mainDEJ2000Declination (J2000.0)pos.eq.dec;meta.mainRefDetection references (1)meta.ref;instr.saturationcharFSimbad column added by the CDSmeta.ref.urlcharSimbadSimbad column added by the CDScharJ/ApJ/643/356/table2Spectral Fits to Transient DetectionsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint[KGP2002]Source identificationmeta.id;meta.maincharObs.DateDate of Observationtime.epoch;obsnullableInstTelescope/Instrument usedmeta.id;instr.obstycharOBSIDObservational identification codemeta.id;obslongCt1? Net counts in detection (1)ctphot.count;em.X-rayintnullableCt2? XMM MOS1 net counts in detectionctphot.count;em.X-rayintnullableCt3? XMM MOS2 net counts in detectionctphot.count;em.X-rayintnullableModelModel used to fit spectrum (2)instr.setup;meta.modelledcharNH? Hydrogen column density1e-21cm**-2phys.columnDensityfloatnullableE_NH? Upper uncertainty limit in NH1e-21cm**-2stat.error;stat.maxfloatnullablee_NH? Uncertainty (or lower limit) in NH1e-21cm**-2stat.errorfloatnullableGamma? Best fit power law slopespect.indexfloatnullableE_Gamma? Upper uncertainty limit in Gammastat.error;stat.maxfloatnullablee_Gamma? Uncertainty (or lower limit) in Gammastat.errorfloatnullableT? Temperature parameter (3)stat.fit.paramfloatnullableE_T? Upper uncertainty limit in Tstat.error;stat.maxfloatnullablee_T? Uncertainty (or lower limit) in Tstat.errorfloatnullablechi2? Model {chi}^2^ valuestat.fit.chi2floatnullableDoF? Degrees of freedomstat.fit.dofintnullableProb? Probability of fit (4)stat.probabilityfloatnullableHR1? First hardness ratio, M-S/M+S (5)phot.fluxfloatnullablee_HR1? Uncertainty in HR1stat.errorfloatnullableHR2? Second hardness ratio, H-S/H+S (6)phot.fluxfloatnullablee_HR2? Uncertainty in HR2stat.errorfloatnullableLXAbsorption-corrected X-ray luminosity in units of 10^36^ erg/s (7)1e+29Wphys.luminosity;em.X-rayfloatE_LX? Upper uncertainty limit in LX1e+29Wstat.error;stat.maxfloatnullablee_LXUncertainty (or lower limit) in LX1e+29Wstat.errorfloat