J/ApJ/759/11ivo://CDS.VizieR/J/ApJ/759/11doi:10.26093/cds/vizier.17590011CDSNeugent K.F.Massey P.Georgy C.2023-04-19T14:25:13Z2014-09-02T12:57:50ZCDS support team

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

cds-question@unistra.frline-intensitiesstellar-spectral-typeswolf-rayet-starsspectroscopygalaxiesWolf-Rayet (WR) stars are evolved massive stars, and the relative number of WC-type and WN-type WRs should vary with the metallicity of the host galaxy, providing a sensitive test of stellar evolutionary theory. However, past studies of the WR content of M31 have been biased toward detecting WC stars, as their emission-line signatures are much stronger than those of WNs. Here, we present the results of a survey covering all of M31's optical disk (2.2deg^2^), with sufficient sensitivity to detect the weaker-lined WN types. We identify 107 newly found WR stars, mostly of WN type. This brings the total number of spectroscopically confirmed WRs in M31 to 154, a number we argue is complete to ~95%, except in regions of unusually high reddening. This number is consistent with what we expect from the integrated H{alpha} luminosity compared to that of M33. The majority of these WRs formed in OB associations around the Population I ring, although 5% are truly isolated. Both the relative number of WC- to WN-type stars as well as the WC subtype distribution suggest that most WRs exist in environments with higher-than-solar metallicities, which is consistent with studies of M31's metallicity. Although the WC to WN ratio we find for M31 is much lower than that found by previous studies, it is still higher than what the Geneva evolutionary models predict. This may suggest that Roche-lobe overflow produces the excess of WC stars observed at high metallicity, or that the assumed rotational velocities in the models are too high.2012ApJ...759...11Nhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/759/11CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toIII/215 : 7th Catalog of Galactic Wolf-Rayet stars (van der Hucht, 2001)III/143 : Spectrophotometry of Wolf-Rayet Stars (Torres-Dodgen+ 1988)J/AJ/143/149 : NIR spectro. of Galactic Wolf-Rayet stars. II. (Shara+, 2012)J/ApJ/733/123 : The Wolf-Rayet content of M33 (NGC 598) (Neugent+, 2011)J/A+A/534/A55 : Deep XMM-Newton Survey of M31 (Stiele+, 2011)J/A+A/509/A61 : Long slit spectroscopy in M31 (Saglia+, 2010)J/ApJ/703/420 : Red supergiants in M31 (Massey+, 2009)J/AJ/134/2474 : H{alpha} em.-line stars in 7 dwarfs galaxies (Massey+, 2007)J/AJ/133/2393 : UBVRI phot. in 7 Local Group dwarfs galaxies (Massey+, 2007)J/AJ/131/2478 : M31 and M33 UBVRI photometry (Massey+, 2006)J/A+A/373/63 : M31 second ROSAT PSPC survey (Supper+, 2001)J/ApJ/505/793 : New WR star in M33 (Massey+, 1998)J/AJ/110/2715 : UBV photometry in NGC 6822, M31 and M33 (Massey+ 1995)J/A+AS/102/251 : Objective-prism survey of M31 em. objects (Meyssonnier+ 1993)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/759/11https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/759/11http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/759/11https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/759/11https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/759/11http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/759/11GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/759/11/m31wr (Spectroscopically confirmed M31 WR stars (tables 2 and 5))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/759/11/m31wr?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/759/11/m31wr?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/759/11/m31wr?GETtext/xml+votable180.050000true9.738291740.52561110.005555555555555556Associated datahttps://cdsarc.cds.unistra.fr/assocdata/?obs_collection=J/ApJ/759/116/2622-2623 2666 2708-2709 27523.322582951404819e-19 3.852589004194616e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/759/11?format=asciidefaultJ/ApJ/759/11/m31wrSpectroscopically confirmed M31 WR stars (tables 2 and 5)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar designation (JHHMMSS.ss+DDMMSS.s for LGGS or XHHMMSS.ss+DDMMSS.s for new) (5)meta.id;meta.maincharNSpTNew spectral type designationsrc.spTypecharf_NSpT[d] 2 new spectra were obtained and comparedmeta.codecharni[e] star not found in our imaging surveymeta.codecharPSpTPrevious spectral typesrc.spTypecharr_PSpTReference for PSpT (4)meta.ref;pos.framecharEW3[2/1160]? Equivalent width of CIII(4650)/HeII(4686) feature0.1nmspect.line.eqWidthintnullableFW3[3/87]? FWHM of CIII(4650)/HeII(4686) feature0.1nmspect.line.widthintnullableEW4[8/1160]? Equivalent width of CIV(5806) line0.1nmspect.line.eqWidthintnullableFW4[15/87]? FWHM of CIV(5806) line0.1nmspect.line.widthintnullableCommentAdditional commentsmeta.notecharrho[0/1] Normalized galactocentric distance {rho} within M31 plane ({rho}=1 is R=95.3")pos.distancefloatSpTSpectral type adoptedsrc.spTypecharf_SpT[f] Spectral type from literature (1)meta.codecharVmag[17.5/22.8]? LGGS Apparent V band magnitudemagphot.mag;em.opt.VfloatnullableB-V[-0.5/0.8]? LGGS (B-V) color indexmagphot.color;em.opt.B;em.opt.VfloatnullableSimbadSimbad column added by the CDSmeta.ref.urlcharAssocOB association (3)meta.id.assoccharVMag[-7.5/-3]? Absolute V band magnitude (2)magphys.magAbsfloatnullableNaNumber of WR stars associated with this OB associationmeta.numberintnullableOIDPrevious identifier (G1)meta.idcharspi370-915nm spectrum (non-interactive)meta.ref.urlcharSpInteractive plot of spectrummeta.ref.urlcharFileName1Name of FITS file in subdirectory specmeta.id;meta.fitscharSp2Interactive plot of second spectrummeta.ref.urlcharFileName2Name of second FITS file (alternative spectrum) in subdirectory specmeta.id;meta.fitscharMJ98Cross-match within 3" with Massey & Johnson, 1998, Cat. J/ApJ/505/793meta.ref.urlintnullable_RAPosition, from LGGS name (right ascension part)degpos.eq.ra;meta.main_DEPosition, from LGGS name (declination part)degpos.eq.dec;meta.main