J/ApJ/826/224ivo://CDS.VizieR/J/ApJ/826/224doi:10.26093/cds/vizier.18260224CDSMassey P.Evans K.A.2018-11-15T11:09:48Z2018-03-12T13:38:22ZCDS support team

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

cds-question@unistra.frgalaxiessupergiant-starsradial-velocitystellar-spectral-typeseffective-temperatureinfrared-photometryWe investigate the red supergiant (RSG) population of M31, obtaining the radial velocities of 255 stars. These data substantiate membership of our photometrically selected sample, demonstrating that Galactic foreground stars and extragalactic RSGs can be distinguished on the basis of B-V, V-R two-color diagrams. In addition, we use these spectra to measure effective temperatures and assign spectral types, deriving physical properties for 192 RSGs. Comparison with the solar metallicity Geneva evolutionary tracks indicates astonishingly good agreement. The most luminous RSGs in M31 are likely evolved from 25-30 M_{sun}_ stars, while the vast majority evolved from stars with initial masses of 20 M_{sun}_ or less. There is an interesting bifurcation in the distribution of RSGs with effective temperatures that increases with higher luminosities, with one sequence consisting of early K-type supergiants, and with the other consisting of M-type supergiants that become later (cooler) with increasing luminosities. This separation is only partially reflected in the evolutionary tracks, although that might be due to the mis-match in metallicities between the solar Geneva models and the higher-than-solar metallicity of M31. As the luminosities increase the median spectral type also increases; i.e., the higher mass RSGs spend more time at cooler temperatures than do those of lower luminosities, a result which is new to this study. Finally we discuss what would be needed observationally to successfully build a luminosity function that could be used to constrain the mass-loss rates of RSGs as our Geneva colleagues have suggested.2016ApJ...826..224Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/826/224CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/145 : Brightest stars in a foreground field of M31II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)J/AJ/96/1884 : BVRJHK photometry of M31 red supergiants (Humphreys+ 1988)J/ApJ/501/153 : VRB photometry of red supergiants (Massey 1998)J/ApJ/703/420 : Red supergiants in M31 (Massey+, 2009)J/ApJ/825/50 : Variable stars in M31 + M33. III. YSGs + RSGs (Gordon+, 2016)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/826/224https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/826/224http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/826/224https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/826/224https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/826/224http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/826/224GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/826/224/table1 (Radial Velocities RSG and Foreground Candidates)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/826/224/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/826/224/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/826/224/table1?GETtext/xml+votable180.050000true9.961916740.89222220.0055555555555555566/2622 2623 2666 2708 2709 27527.952274030004205e-20 1.0188844282367877e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/826/224?format=asciiInfrareddefaultJ/ApJ/826/224/table1Radial Velocities RSG and Foreground CandidatesSimbadNameSimbad column added by the CDSmeta.idcharX/RRatio (1)pos.angDistancefloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDStellar identifier (JHHMMSS.SS+DDMMSS.S)meta.id;meta.maincharRV-M31M31 radial velocitykm/sphys.veloc;pos.heliocentricfloatRV-ObsObserved radial velocitykm/sphys.veloc;pos.heliocentricfloate_RV-ObsUncertainty in RV-Obskm/sstat.errorfloatNobs[1/6] Number of observationsmeta.numberintTDRTonry & Davis (1979AJ.....84.1511T) r-parameterstat.correlationfloatRV-M09? Old Massey et al. (2009, J/ApJ/703/420) radial velocityphys.veloc;pos.heliocentricfloatnullablePType[RSG fgd] Photometric type (2)src.classcharComAdditional commentmeta.notecharCat-linkDisplay data from Massey et al. (2009, J/ApJ/703/420)meta.ref.urlintnullable_RAPosition from stellar identifier (right ascension part)degpos.eq.ra;meta.main_DEPosition from stellar identifier (declination part)degpos.eq.dec;meta.mainJ/ApJ/826/224/table2Physical PropertiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDStellar identifier (JHHMMSS.SS+DDMMSS.S)meta.id;meta.maincharSpTypeSpectral typesrc.spTypecharTeff? Effective temperatureKphys.temperature.effectiveintnullableKsmag? Apparent K_s_ band magnitudemagphot.mag;em.IR.Kfloatnullableu_Ksmag[:] Uncertainty flag on Ksmagmeta.code.errorcharSource[MFX] Data source code (1)meta.codecharKMag? Absolute K band magnitudemagphys.magAbs;em.IR.KfloatnullablelogL? Log luminosity relative to solarlog(solLum)phys.luminosityfloatnullableRad? Radius relative to solarsolRadphys.angSize;srcintnullable