J/MNRAS/465/4180ivo://CDS.VizieR/J/MNRAS/465/4180doi:10.26093/cds/vizier.74654180CDSPrichard L.J.Guhathakurta P.Hamren K.M.Dalcanton J.J.Dorman C.E.,Seth A.C.Williams B.F.Damon G.A.Ilango A.Ilango M.2024-08-16T20:20:20Z2019-09-12T14:46:24ZCDS support team

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

cds-question@unistra.frgalaxiesemission-line-starshst-photometryradial-velocityWe present a sample of 224 stars that emit H{alpha} (H{alpha} stars) in the Andromeda galaxy (M31). The stars were selected from ~5000 spectra, collected as part of the Spectroscopic and Photometric Landscape of Andromeda's Stellar Halo survey using Keck II/DEIMOS. We used six-filter Hubble Space Telescope photometry from the Panchromatic Hubble Andromeda Treasury survey to classify and investigate the properties of the H{alpha} stars. We identified five distinct categories of H{alpha} star: B-type main-sequence (MS) stars, 'transitioning'-MS (T-MS) stars, red core He burning (RHeB) stars, non-C-rich asymptotic giant branch (AGB) stars, and C-rich AGB stars. We found that ~12 per cent of B-type stars exhibit H{alpha} emission (Be stars). The frequency of Be to all B stars is known to vary with the metallicity of their environment. Comparing this proportion of Be stars with other environments around the Local Group, the result could indicate that M31 is more metal-rich than the Milky Way. We predict that the 17 T-MS H{alpha} stars are Be stars evolving off the MS with fading H{alpha} emission. We separated RHeB from AGB H{alpha} stars. We conclude that the 61 RHeB and AGB stars are likely to be long-period variables. We found that ~14 per cent of C-rich AGB stars (C stars) emit H{alpha}, which is an upper limit for the ratio of C-rich Miras to C stars. This catalogue of H{alpha} stars will be useful to constrain stellar evolutionary models, calibrate distance indicators for intermediate-age populations, and investigate the properties of M31.2017MNRAS.465.4180Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/465/4180CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/465/4180https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/465/4180http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/465/4180https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/465/4180https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/465/4180http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/465/4180GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/465/4180/tablea1 (List of selected H{alpha} stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/465/4180/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/465/4180/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/465/4180/tablea1?GETtext/xml+votable180.050000true11.0532083341.1140.0055555555555555566/2623 2666 2709 27521.0590977079788917e-19 7.605786964834612e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/465/4180?format=asciidefaultJ/MNRAS/465/4180/tablea1List of selected H{alpha} starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIndexIndexmeta.idintNameObject namemeta.id;meta.maincharClassClassificationsrc.classcharMaskDEIMOS mask namemeta.id;instrcharSlitMask slit numbermeta.notecharGrate[600] Gratemm**-1spect.resolutionfloatRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainEWH{alpha} equivalent width0.1nmspect.line.eqWidth;em.line.Halphadoublee_EWrms uncertainty on EW0.1nmstat.error;spect.line.eqWidthdoublesigmaVelocity dispersionkm/sphys.veloc.dispersioninte_sigmarms uncertainty on sigmakm/sstat.errorintHVHeliocentric velocitykm/sspect.dopplerVeloc;pos.heliocentricfloatRdpDeprojected radiuskpcphys.size.radiusfloatF275W? PHAT HST F275W magnitude (UV)magphot.mag;em.UV.200-300nmfloatnullableF336W? PHAT HST F336W magnitude (UV)magphot.mag;em.opt.UfloatnullableF475W? PHAT HST F475W magnitude (optical)magphot.mag;em.opt.BfloatnullableF814W? PHAT HST F814W magnitude (far-red)magphot.mag;em.opt.IfloatnullableF110W? PHAT HST F110W magnitude (NIR)magphot.mag;em.IR.HfloatnullableF160W? PHAT HST F160W magnitude (NIR)magphot.mag;em.IR.Hfloatnullable