J/ApJ/610/247ivo://CDS.VizieR/J/ApJ/610/247doi:10.26093/cds/vizier.16100247CDSDi Stefano R.Kong A.K.H.Greiner J.Primini F.A.Garcia M.R.,Barmby P.Massey P.Hodge P.W.Williams B.F.Murray S.S.Curry S.,Russo T.A.2017-10-11T05:12:55Z2015-12-04T10:39:23ZCDS support team

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

cds-question@unistra.frgalaxiesx-ray-sourcesWe report on very soft X-ray sources (VSSs) in M31. In a survey that was most sensitive to soft sources in four 8'x8' regions covered by Chandra's ACIS-S S3 CCD, we find 33 VSSs that appear to belong to M31. Fifteen VSSs have spectral characteristics mirroring the supersoft X-ray sources studied in the Magellanic Clouds and Milky Way (kT_eff_<=100eV); we therefore call these "classical" supersoft sources, or simply supersoft sources (SSSs). Eighteen VSSs may have either small (<10%) hard components or slightly higher effective temperatures (but still less than 350eV). We refer to these VSSs as quasi-soft sources (QSSs).2004ApJ...610..247Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/610/247CatalogResearchIsServedByTAP 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)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/610/247https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/610/247http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/610/247https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/610/247https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/610/247http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/610/247GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/610/247/table1 (VSS source list)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/610/247/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/610/247/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/610/247/table1?GETtext/xml+votable180.050000true9.5787540.2593060.0055555555555555566/2622 2623 2666 2705 2708 2709https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/610/247?format=asciiX-raydefaultJ/ApJ/610/247/table1VSS source listrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint[KGP2002]Object identification (1)meta.id;meta.maincharRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainSCtsSoft counts (2)ctphot.count;em.X-rayfloatSS/NSoft signal to noise ratiostat.snrfloatMCtsMedium counts (2)ctphot.count;em.X-rayfloatMS/NMedium signal to noise ratiostat.snrfloatHCtsHard counts (2)ctphot.count;em.X-rayfloatHS/NHard signal to noise ratiostat.snrfloatHR1Hardness ratio 1 (3)phot.flux;arith.ratiofloatHR2Hardness ratio 2 (3)phot.flux;arith.ratiofloatCRateCount rate in units of 10^-3^ct/sct/ksphot.count;em.X-rayfloatCatCategory (4)meta.codecharl_Dist[~] Limit Flag on Distmeta.code.errorcharDistAngular distance to the nearest X-ray sourcearcsecpos.angDistancecharSimbadSimbad column added by the CDSmeta.ref.urlchar