J/ApJ/691/672ivo://CDS.VizieR/J/ApJ/691/672doi:10.26093/cds/vizier.16910672CDSOliveira I.Merin B.Pontoppidan K.M.van Dishoeck E.F.Overzier R.A.,Hernandez J.Sicilia-Aguilar A.Eiroa C.Montesinos B.2023-12-19T10:39:54Z2011-03-08T13:08:19ZCDS support team

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

cds-question@unistra.fryoung-stellar-objectsstellar-spectral-typesextinctionastronomical-object-identificationmolecular-cloudsWe report on the results of an optical spectroscopic survey designed to confirm the youth and determine the spectral types among a sample of young stellar object (YSO) candidates in the Serpens molecular cloud. We observed 150 infrared (IR) excess objects previously discovered by the Spitzer Legacy Program "From Molecular Cores to Planet-Forming Disks" (c2d), bright enough for subsequent Spitzer/InfraRed Spectrograph (IRS) spectroscopy. We obtained 78 optical spectra of sufficient signal-to-noise for analysis. Extinctions, effective temperatures, and luminosities are estimated for this sample, and used to construct Hertzsprung-Russell (H-R) diagrams for the population. We identified 20 background giants contaminating the sample, based on their relatively high extinction, position in the H-R diagram, the lack of H{alpha} emission and relatively low IR excess. Such strong background contamination (25%) is consistent with the location of Serpens being close to the Galactic plane (5{deg} Galactic latitude). The remaining 58 stars (75%) were all confirmed to be young, mostly K- and M-type stars that are presumed to belong to the cloud. Our analysis shows that the majority of the IR excess objects detected in Serpens are actively accreting, young T-Tauri stars.2009ApJ...691..672Ohttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/691/672CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJS/181/321 : Properties of Spitzer c2d dark clouds (Evans+, 2009)J/ApJ/684/1240 : Prestellar cores in Perseus, Serpens and Ophiuchus (Enoch+,J/ApJ/663/1149 : Spitzer survey of Serpens YSO population (Harvey+, 2007)J/A+A/463/275 : Chandra obs. of Serpens star-forming region (Giardino+, 2007)J/ApJ/669/493 : Spitzer/Chandra YSOs in Serpens cloud core (Winston+, 2007)J/A+A/421/623 : ISOCAM survey of YSOs in Serpens Cloud Core (Kaas+, 2004)J/A+A/337/403 : Low-mass stars evolutionary models (Baraffe+ 1998)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/691/672https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/691/672http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/691/672https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/691/672https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/691/672http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/691/672GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/691/672/ysocand (Stellar parameters for the YSO candidates in Serpens (tables 2 and 3 of the paper))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/691/672/ysocand?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/691/672/ysocand?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/691/672/ysocand?GETtext/xml+votable180.050000true276.9742917-0.04263890.0055555555555555565/7590 6/30366https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/691/672?format=asciidefaultJ/ApJ/691/672/ysocandStellar parameters for the YSO candidates in Serpens (tables 2 and 3 of the paper)SeqRunning number (<[OMP2009] NNN> in Simbad)meta.id;meta.mainintprimaryYSOmeta.ref.urlcharHMH07? Identification from Harvey et al. 2007, Cat. J/ApJ/663/1149 (<[HMH2007] NNN> in Simbad)meta.idintnullableSSTc2dSSTc2d identification (HHMMSSss+DDMMSSs) (<SSTc2d JHHMMSS.s+DDMMSS> in Simbad)meta.idcharSimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintalpha{alpha}_2-24um_ slope (1)spect.indexfloatSpTMK spectral typesrc.spTypechare_SpTSubtype uncertaintystat.errorfloatAVobsExtinction found in this workmagphys.absorptionfloatAVClExtinction found by "c2d" over 5' regionmagphys.absorptionfloatAV? Final extinctionmagphys.absorptionfloatnullablef_Seq[a,bc ] Flag on Seq (1)meta.codecharTeffEffective temperatureKphys.temperature.effectiveintE_TeffPositive error on TeffKstat.error;stat.maxinte_TeffNegative error on TeffKstat.error;phys.temperature.effectiveintL*? LuminositysolLumphys.luminosityfloatnullableE_L*? Positive error on L*solLumstat.error;stat.maxfloatnullablee_L*? Negative error on L*solLumstat.errorfloatnullableAgeB? Age (2)Myrtime.agefloatnullableE_AgeB? Positive error on AgeBMyrstat.error;stat.maxfloatnullablee_AgeB? Negative error on AgeBMyrstat.errorfloatnullableMassB? Mass (2)solMassphys.massfloatnullableE_MassB? Positive error on MassBsolMassstat.error;stat.maxfloatnullablee_MassB? Negative error on MassBsolMassstat.errorfloatnullableAgeS? Age (3)Myrtime.agefloatnullableE_AgeS? Positive error on AgeSMyrstat.error;stat.maxfloatnullablee_AgeS? Negative error on AgeSMyrstat.errorfloatnullableMassS? Mass (3)solMassphys.massfloatnullableE_MassS? Positive error on MassSsolMassstat.error;stat.maxfloatnullablee_MassS? Negative error on MassSsolMassstat.errorfloatnullable_RAPositions from SSTc2d name (right ascension part)degpos.eq.ra;meta.main_DEPositions from SSTc2d name (declination part)degpos.eq.dec;meta.mainJ/ApJ/691/672/table4H{alpha} equivalent widths and line widths and mass accretion rates for YSOs in SerpensrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqRunning number (<[OMP2009] NNN> in Simbad)meta.id;meta.mainintEWHa? H{alpha} (6563{AA}) equivalent width (positive value = emission)spect.line.eqWidthfloatnullablef_EWHa[t] t for classical T Tauri star (CTTS) based on EWHameta.codecharHa10? H{alpha} full width at 10% of the peak intensitykm/sspect.line.widthintnullablee_Ha10? Ha10 uncertaintykm/sstat.errorintnullablef_Ha10[t] t for CTTS based on Ha10meta.codecharlogdM/dt? Mass accretion ratelog(solMass.yr**-1)phys.mass.lossfloatnullablee_logdM/dt? logM uncertaintylog(solMass.yr**-1)stat.errorfloatnullable