J/ApJ/933/77ivo://CDS.VizieR/J/ApJ/933/77doi:10.26093/cds/vizier.19330077CDSZhou X.Herczeg G.J.Liu Y.Fang M.Kuhn M.2026-03-30T20:05:40Z2024-10-09T15:10:07ZCDS support team

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

cds-question@unistra.frstar-forming-regionsstellar-agesphotometryvisible-astronomyinfrared-astronomyeffective-temperaturestellar-massesThe Serpens Molecular Cloud is one of the most active star-forming regions within 500pc, with over 1000 young stellar objects (YSOs) at different evolutionary stages. The ages of the member stars inform us about the star formation history of the cloud. In this paper, we develop a spectral energy distribution (SED) fitting method for nearby evolved (diskless) young stars from members of the Pleiades to estimate their ages, with a temperature scale adopted from APOGEE spectra. When compared with literature temperatures of selected YSOs in Orion, the SED fits to cool (<5000K) stars have temperatures that differ by an average of <=50K and have a scatter of ~210K for both disk-hosting and diskless stars. We then apply this method to YSOs in the Serpens Molecular Cloud to estimate ages of optical members previously identified from Gaia DR2 astrometry data. The optical members in Serpens are concentrated in different subgroups with ages from ~4 to ~22Myr; the youngest clusters, W40 and Serpens South, are dusty regions that lack enough optical members to be included in this analysis. These ages establish that the Serpens Molecular Cloud has been forming stars for much longer than has been inferred from infrared surveys.2022ApJ...933...77Zhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/933/77CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)II/328 : AllWISE Data Release (Cutri+ 2013)II/336 : AAVSO Photometric All Sky Survey (APASS) DR9 (Henden+, 2016)II/349 : The Pan-STARRS release 1 (PS1) Survey - DR1 (Chambers+, 2016)I/350 : Gaia EDR3 (Gaia Collaboration, 2020)I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)J/A+A/492/277 : VOSA. An application to Collinder 69 open cluster (Bayo, 2008)J/ApJ/677/401 : X-ray properties of protostars in ONC (Prisinzano, 2008)J/AJ/144/192 : Spitzer survey of Orion A and B. I. YSO catalog (Megeath, 2012)J/ApJS/207/5 : YSOs in Lynds 1641: disks, accretion & SFH (Fang+, 2013)J/ApJS/209/29 : MYStIX: Mid-IR observations and catalogs (Khun+, 2013)J/AJ/153/188 : Spectroscopy of the foreground pop in Orion A (Fang+, 2017)J/ApJS/229/28 : SFiNCs: X-ray & IR source cat. and membership (Getman+, 2017)J/ApJ/878/111 : Members in Serpens MoCl with Gaia DR2 (Herczeg+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/933/77https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/933/77http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/933/77https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/933/77https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/933/77http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/933/77GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/933/77/table5 (Fits of Serpens members)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/933/77/table5?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/933/77/table5?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/933/77/table5?GETtext/xml+votable180.050000true289.6909910.803270.005555555555555556Cone search capability for table J/ApJ/933/77/regions (Proper motions and radial velocities of Serpens groups and Collinder 359 (Table 8) and ages of Serpens groups (Table 6))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/933/77/regions?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/933/77/regions?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/933/77/regions?GETtext/xml+votable180.050000true277.511.080.0055555555555555564/1897 5/7391 7562-7563 7584-7585 7587 6/30228 30243-30244 30246-30247 30256 30258-30259 30264 30266-30267 30271 30344-30345 30373 30384-30385 30388 30402 30620-30621 30623 31757https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/933/77?format=asciiOpticalInfrareddefaultJ/ApJ/933/77/table5Fits of Serpens membersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGaiaEDR3Gaia EDR3 identifiermeta.id;meta.mainRegRegionmeta.id.parentcharSimbadSimbad column added by the CDSmeta.ref.urlcharAge[1/47.8]? AgeMyrtime.agefloatnullableRA_ICRSGaia EDR3 right Ascension (ICRS) at Ep=2016.0degpos.eq.ra;meta.mainDE_ICRSGaia EDR3 Declination (ICRS) at Ep=2016.0degpos.eq.dec;meta.mainDist[336/639] Distance from Gaia EDR3 parallaxpcpos.distancefloatTeff[3005/9689]? Surface effective temperatureKphys.temperature.effectiveintnullableAv[0/6]? V-band extinctionmagphys.absorptionfloatnullablelogL[-1.75/2.16]? log of luminositylog(solLum)phys.luminosityfloatnullableMstar[0.09/3.5]? Stellar masssolMassphys.massfloatnullableDisk? Flag on disk (1)meta.codeintnullableFlagFlag (=1) if used in calculating cluster agesmeta.code.errorintJ/ApJ/933/77/regionsProper motions and radial velocities of Serpens groups and Collinder 359 (Table 8) and ages of Serpens groups (Table 6)e_pmDE[0.06/0.7]? Standard error ({sigma}) on pmDEmas/yrstat.error;pos.pm;pos.eq.decfloatnullableRV[-12.1/11]? Radial velocitykm/sspect.dopplerVelocfloatnullablee_RV[2.1/5.5]? Sigma uncertainty in RVkm/sstat.error;spect.dopplerVelocfloatnullableNs[2/11]? Number of stars to calculate RVmeta.numberintnullableNmNumber of star members for this group (link to Table5)meta.numberintnullableSimbadNameSimbad column added by the CDSmeta.idcharnullableAgeD[2.9/9.5]? Age of diskMyrtime.agefloatnullablee_AgeD[0.5/9.3]? Error on AgeDMyrstat.error;time.agefloatnullableAgeDl[4/22]? Age of disklessMyrtime.agefloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRegRegion identifier as in Table 5 (+Collinder 359)meta.id;meta.maincharprimarypmRA[0.64/3.1]? Proper motion in right ascensionmas/yrpos.pm;pos.eq.rafloatnullablee_pmRA[0.16/0.6]? Standard error ({sigma}) on pmRAmas/yrstat.error;pos.pm;pos.eq.rafloatnullablepmDE[-10.3/-8.1]? Proper motion in declinationmas/yrpos.pm;pos.eq.decfloatnullablee_AgeDl[0.2/1.6]? Error on AgeDlMyrstat.error;time.agefloatnullableAgeTot[4/22]? Age of total (1)Myrtime.agefloatnullablee_AgeTot[0.2/1.4]? Error on AgeTotMyrstat.error;time.agefloatnullablefdisk[0/0.22]? Disk fractionstat.fit.paramfloatnullable_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.main