J/MNRAS/439/2211ivo://CDS.VizieR/J/MNRAS/439/2211doi:10.26093/cds/vizier.74392211CDSKamath D.Wood P.R.Van Winckel H.2024-08-08T20:12:44Z2015-01-22T12:51:32ZCDS support team

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

cds-question@unistra.frmagellanic-cloudsyoung-stellar-objectsgiant-starsphotometryspectroscopyWe have carried out a search for optically visible post-asymptotic giant branch (post-AGB) candidates in the Small Magellanic Cloud (SMC). First, we used mid-IR observations from the Spitzer Space Telescope to select optically visible candidates with excess mid-IR flux and then we obtained low-resolution optical spectra for 801 of the candidates. After removing poor-quality spectra and contaminants, such as M-stars, C-stars, planetary nebulae, quasi-stellar objects and background galaxies, we ended up with a final sample of 63 high-probability post-AGB/RGB candidates of A-F spectral type. From the spectral observations, we estimated the stellar parameters: effective temperature (T_eff_), surface gravity (logg) and metallicity ([Fe/H]). We also estimated the reddening and deduced the luminosity using the stellar parameters combined with photometry. For the post-AGB/RGB candidates, we found that the metallicity distribution peaks at [Fe/H]~-1.00dex. Based on a luminosity criterion, 42 of these 63 sources were classified as post-red giant branch (post-RGB) candidates and the remaining 21 as post-AGB candidates. From the spectral energy distributions, we were able to infer that 6 of the 63 post-AGB/RGB candidates have a surrounding circumstellar shell suggesting that they are single stars, while 27 of the post-AGB/RGB candidates have a surrounding disc, suggesting that they lie in binary systems. For the remaining 30 post-AGB/RGB candidates the nature of the circumstellar environment was unclear. Variability is displayed by 38 of the 63 post-AGB/RGB candidates with the most common variability types being the Population II Cepheids (including RV-Tauri stars) and semiregular variables. This study has also revealed a new RV Tauri star in the SMC, J005107.19-734133.3, which shows signs of s-process enrichment. From the numbers of post-AGB/RGB stars in the SMC, we were able to estimate evolutionary rates. We find that the number of post-AGB and post-RGB candidates that we have identified are in good agreement with the stellar evolution models with some mass-loss in the post-AGB phase and a small amount of re-accretion in the lower luminosity post-RGB phase. This study also resulted in a new sample of 40 young stellar objects (YSOs) of A-F spectral type. The 40 YSO candidates for which we could estimate stellar parameters are luminous and of high mass (~3-10M_{sun}_). They lie on the cool side of the usually adopted birthline in the HR-diagram. This line separates visually obscured protostars from optically visible pre-main-sequence stars, meaning that our YSO candidates have become optically visible in the region of the HR diagram usually reserved for obscured protostars. Additionally, we also identified a group of 63 objects whose spectra are dominated by emission lines and in some cases, a significant UV continuum. These objects are very likely to be either hot post-AGB/RGB candidates or luminous YSOs.2014MNRAS.439.2211Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/439/2211CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)II/305 : SAGE LMC and SMC IRAC Source Catalog (IPAC 2009)II/311 : WISE All-Sky Data Release (Cutri+ 2012)J/AJ/123/855 : Magellanic Clouds Photometric Survey (MCPS): the SMChttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/439/2211https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/439/2211http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/439/2211https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/439/2211https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/439/2211http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/439/2211GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/439/2211/table1 (Photometric data)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/439/2211/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/439/2211/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/439/2211/table1?GETtext/xml+votable180.050000true6.07133306-73.825611110.0055555555555555565/8323 8326 8329 8332 6/33285 33287 33291 33296 33298-33299 33313 33315 33321 33324-33325 33327 333361.0763920601544068e-21 6.118840631666147e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/439/2211?format=asciiOpticaldefaultJ/MNRAS/439/2211/table1Photometric datarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTabindicates the table with the sourcemeta.codecharNameName (JHHMMSS.dd+DDMMSS.s)meta.id;meta.maincharprimaryRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainUmag? U magnitude from MCPS (1)magphot.mag;em.opt.UfloatnullableBmag? B magnitude from MCPS (1)magphot.mag;em.opt.BfloatnullableVmag? V magnitude from MCPS (1)magphot.mag;em.opt.VfloatnullableImag? I magnitude from MCPS (1) (or DENIS if not in MCPS) (1)magphot.mag;em.opt.IfloatnullableJmag? 2MASS J magnitudemagphot.mag;em.IR.JfloatnullableHmag? 2MASS H magnitudemagphot.mag;em.IR.HfloatnullableKmag? 2MASS Ks magnitudemagphot.mag;em.IR.KfloatnullableW1mag? WISE W1 magnitude (3.35{mu}m)magphot.mag;em.IR.3-4umfloatnullable[3.6]? Spitzer/IRAC 3.6{mu}m magnitudemagphot.mag;em.IR.3-4umfloatnullable[4.5]? Spitzer/IRAC 4.5{mu}m magnitudemagphot.mag;em.IR.4-8umfloatnullableW2mag? WISE W2 magnitude (4.6{mu}m)magphot.mag;em.IR.4-8umfloatnullable[5.8]? Spitzer/IRAC 5.8{mu}m magnitudemagphot.flux.density;em.IR.4-8umfloatnullable[8.0]? Spitzer/IRAC 8.0{mu}m magnitudemagphot.flux.density;em.IR.8-15umfloatnullableW3mag? WISE W3 magnitude (11.6{mu}m)magphot.flux.density;em.IR.8-15umfloatnullableW4mag? WISE W4 magnitude (22.1{mu}m)magphot.flux.density;em.IR.15-30umfloatnullable[24]? Spitzer/MIPS 24{mu}m magnitudemagphot.flux.density;em.IR.15-30umfloatnullable[70]? Spitzer/MIPS 70{mu}m magnitudemagphot.flux.density;em.IR.30-60umfloatnullable[160]? Spitzer/MIPS 160{mu}m magnitudemagphot.flux.density;em.mm.1500-3000GHzfloatnullableLobs[93/42500] Observed luminositysolLumphys.luminosityintTeff[3500/19000] Effective photometric temperatureKphys.temperature.effectiveintJ/MNRAS/439/2211/table45The observational and stellar parameters for the Q1 and Q2 post-AGB/RGB candidates (tables 4 and 5)SimbadNameSimbad column added by the CDSmeta.idcharspShow the spectrummeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintQSimbad column added by the CDSmeta.code.qualcharn_Seq[AB] Code for [Fe/H] estimates (1)meta.notecharSeq[1/63] Sequential numbermeta.recordintplotShow spectral typing resultmeta.ref.urlcharNameSource name (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharn_Teff[bc] Teff was increased to estimate E(B-V) (2)meta.notecharTeff[3950/17000] Effective temperatureKphys.temperature.effectiveintlogg[0/4] Surface gravitylog(cm.s**-2)phys.gravityfloat[Fe/H][-2.3/-0.1] Metallicitylog(Sun)phys.abund.ZfloatE(B-V)[0/1.2] Total redenning estimated (2)magphot.color.excessfloatLobs[100/20000] Observed luminosity corrected for foreground extinctionsolLumphys.luminosityintLphot[75/22300] Photospheric luminositysolLumphys.luminosityintTypeEstimated evolutionary status for post-AGB/RGB candidates (p-RGB for a post-RGB star, p-AGB for a post-AGB star)src.classcharRV[40/300] Radial velocitykm/sphys.veloc;pos.heliocentricfloate_RV[1/31] rms uncertainty on RVkm/sstat.errorfloatMass[0.3/1]? Derived mass of the post-AGB/RGB candidate (see Section 4)solMassphys.massfloatnullableSEDSED comments (Disc, Shell or Uncertain)meta.codecharCatCatalogue information (3)meta.notecharJ/MNRAS/439/2211/table67The observational and stellar parameters for the Q1 and Q2 YSO candidates (tables 6 and 7)SimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintQSimbad column added by the CDSmeta.code.qualcharn_Seq[AB] Code for [Fe/H] estimates (1)meta.notecharSeq[1/63] Sequential numbermeta.recordintspShow the spectrummeta.ref.urlcharplotShow spectral typing resultmeta.ref.urlcharNameSource name (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharn_Teff[bc] Teff was increased to estimate E(B-V) (2)meta.notecharTeff[3950/17000] Effective temperatureKphys.temperature.effectiveintlogg[0/4] Surface gravitylog(cm.s**-2)phys.gravityfloat[Fe/H][-2.3/-0.1] Metallicitylog(Sun)phys.abund.ZfloatE(B-V)[0/1.2] Total redenning estimated (2)magphot.color.excessfloatLobs[100/20000] Observed luminosity corrected for foreground extinctionsolLumphys.luminosityintLphot[75/22300] Photospheric luminositysolLumphys.luminosityintTypeEstimated evolutionary status for post-AGB/RGB candidates (p-RGB for a post-RGB star, p-AGB for a post-AGB star)src.classcharRV[40/300] Radial velocitykm/sphys.veloc;pos.heliocentricfloate_RV[1/31] rms uncertainty on RVkm/sstat.errorfloatMass[0.3/1]? Derived mass of the post-AGB/RGB candidate (see Section 4)solMassphys.massfloatnullableSEDSED comments (Disc, Shell or Uncertain)meta.codecharCatCatalogue information (3)meta.notecharJ/MNRAS/439/2211/tablea1The list of candidates with emission lines and UV continuumSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintn_Name[Y] Y for Previously identified YSOsmeta.notecharNameName (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharONamesPrevious identification (G1)meta.idcharLobs[200/42500] Observed luminosity (computed by integrating under the flux distribution at observed wavelengths)solLumphys.luminosityintTypeType (hot pA/R = hot post-AGB/RGB candidates)src.classcharHa[e0a] H{alpha} 6563{AA} line information (G2)meta.codecharu_Ha[:] Uncertainty flag on Ha (G3)meta.code.errorcharHb[e0a] H{beta} 4861{AA} line information (G2)meta.codecharu_Hb[:] Uncertainty flag on Hb (G3)meta.code.errorcharHg[e0a] H{gamma} 4341{AA} line information (G2)meta.codecharu_Hg[:? ] Uncertainty flag on Hg (G3)meta.code.errorchar[OIII]1[e0a] [OIII] 4659{AA} line information (G2)meta.codecharu_[OIII]1[:?] Uncertainty flag on [OIII]1 (G3)meta.code.errorchar[OIII]2[e0a] [OIII] 5007{AA} line information (G2)meta.codecharu_[OIII]2[:?] Uncertainty flag on [OIII]2 (G3)meta.code.errorcharHeI1[e0a] HeI 4471{AA} line information (G2)meta.codecharu_HeI1[:?] Uncertainty flag on HeI1 (G3)meta.code.errorcharHeI2[e0a?] HeI 5876{AA} line information (G2)meta.codecharu_HeI2[:?] Uncertainty flag on HeI2 (G3)meta.code.errorchar[SII]1[e0a] [SII] 6717{AA} line information (G2)meta.codecharu_[SII]1[:?] Uncertainty flag on [SII]1 (G3)meta.code.errorchar[SII]2[e0a] [SII] 6731{AA} line information (G2)meta.codecharu_[SII]2[:?] Uncertainty flag on [SII]2 (G3)meta.code.errorchar[NII]1[e0a] [NII] 6548{AA} line information (G2)meta.codecharu_[NII]1[:?] Uncertainty flag on [NII]1 (G3)meta.code.errorchar[NII]2[e0a] [NII] 6584{AA} line information (G2)meta.codecharu_[NII]2[:?] Uncertainty flag on [NII]2 (G3)meta.code.errorcharCaII1[e0a] CaII 8498{AA} line information (G2)meta.codecharu_CaII1[:?] Uncertainty flag on CaII1 (G3)meta.code.errorcharCaII2[e0a] CaII 8542{AA} line information (G2)meta.codecharCaII3[e0a] CaII 8662{AA} line information (G2)meta.codecharLi[e0a] Li 6708{AA} line information (G2)meta.codecharu_Li[:?] Uncertainty flag on Li (G3)meta.code.errorcharBa[e0a] Ba 4554{AA} line information (G2)meta.codecharPa[e0a] Pa line information (G2)meta.codecharu_Pa[:? ] Uncertainty flag on Pa (G3)meta.code.errorcharJ/MNRAS/439/2211/tableb1The M-stars in our sampleSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameName (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharn_Name[*] Note on Name (1)meta.notecharJ/MNRAS/439/2211/tableb2The C-stars in our sampleSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameName (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharn_Name[*] Note on Name (1)meta.notecharJ/MNRAS/439/2211/tableb3The new and previously known PN candidates in our sampleSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintf_Name[ui] Previously (u)ncatalogued or (i)dentified PNemeta.codecharNameName (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharn_Name[*] Note on Name (1)meta.notecharONamesPrevious identification (G1)meta.idcharHa[e0a] H{alpha} 6563{AA} line information (G2)meta.codecharu_Ha[:?] Uncertainty flag on Ha (G3)meta.code.errorcharHb[e0a] H{beta} 4861{AA} line information (G2)meta.codecharu_Hb[:?] Uncertainty flag on Hb (G3)meta.code.errorcharHg[e0a] H{gamma} 4341{AA} line information (G2)meta.codecharu_Hg[:?] Uncertainty flag on Hg (G3)meta.code.errorchar[OIII]1[e0a] [OIII] 4659{AA} line information (G2)meta.codecharu_[OIII]1[:?] Uncertainty flag on [OIII]1 (G3)meta.code.errorchar[OIII]2[e0a] [OIII] 5007{AA} line information (G2)meta.codecharu_[OIII]2[:?] Uncertainty flag on [OIII]2 (G3)meta.code.errorcharHeI1[e0a] HeI 4471{AA} line information (G2)meta.codecharu_HeI1[:?] Uncertainty flag on HeI1 (G3)meta.code.errorcharHeI2[e0a] HeI 5876{AA} line information (G2)meta.codecharu_HeI2[:?] Uncertainty flag on HeI2 (G3)meta.code.errorchar[SII]1[e0a] [SII] 6717{AA} line information (G2)meta.codecharu_[SII]1[:?] Uncertainty flag on [SII]1 (G3)meta.code.errorchar[SII]2[e0a] [SII] 6731{AA} line information (G2)meta.codecharu_[SII]2[:?] Uncertainty flag on [SII]2 (G3)meta.code.errorchar[NII]1[e0a] [NII] 6548{AA} line information (G2)meta.codecharu_[NII]1[:?] Uncertainty flag on [NII]1 (G3)meta.code.errorchar[NII]2[e0a] [NII] 6584{AA} line information (G2)meta.codecharu_[NII]2[:?] Uncertainty flag on [NII]2 (G3)meta.code.errorcharCaII1[e0a] CaII 8498{AA} line information (G2)meta.codecharu_CaII1[:?] Uncertainty flag on CaII1 (G3)meta.code.errorcharCaII2[e0a] CaII 8542{AA} line information (G2)meta.codecharu_CaII2[:?] Uncertainty flag on CaII2 (G3)meta.code.errorcharCaII3[e0a] CaII 8662{AA} line information (G2)meta.codecharu_CaII3[:?] Uncertainty flag on CaII3 (G3)meta.code.errorcharLi[e0a] Li 6708{AA} line information (G2)meta.codecharu_Li[:?] Uncertainty flag on Li (G3)meta.code.errorcharBa[e0a] Ba 4554{AA} line information (G2)meta.codecharu_Ba[:?] Uncertainty flag on Ba (G3)meta.code.errorcharPa[e0a] Pa line information (G2)meta.codecharu_Pa[:?] Uncertainty flag on Pa (G3)meta.code.errorchar