J/ApJ/787/108ivo://CDS.VizieR/J/ApJ/787/108doi:10.26093/cds/vizier.17870108CDSGetman K.V.Feigelson E.D.Kuhn M.A.Broos P.S.Townsley L.K.,Naylor T.Povich M.S.Luhman K.L.Garmire G.P.2017-09-04T08:02:16Z2017-07-06T12:24:03ZCDS support team

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

cds-question@unistra.frstellar-agesopen-star-clustersx-ray-sourcesgalaxy-classification-systemsinfrared-photometryA major impediment to understanding star formation in massive star-forming regions (MSFRs) is the absence of a reliable stellar chronometer to unravel their complex star formation histories. We present a new estimation of stellar ages using a new method that employs near-infrared (NIR) and X-ray photometry, Age_JX_. Stellar masses are derived from X-ray luminosities using the L_X_-M relation from the Taurus cloud. J-band luminosities are compared to mass-dependent pre-main-sequence (PMS) evolutionary models to estimate ages. Age_JX_ is sensitive to a wide range of evolutionary stages, from disk-bearing stars embedded in a cloud to widely dispersed older PMS stars. The Massive Young Star-Forming Complex Study in Infrared and X-ray (MYStIX) project characterizes 20 OB-dominated MSFRs using X-ray, mid-infrared, and NIR catalogs. The Age_JX_ method has been applied to 5525 out of 31784 MYStIX Probable Complex Members. We provide a homogeneous set of median ages for over 100 subclusters in 15 MSFRs; median subcluster ages range between 0.5 Myr and 5 Myr. The important science result is the discovery of age gradients across MYStIX regions. The wide MSFR age distribution appears as spatially segregated structures with different ages. The Age_JX_ ages are youngest in obscured locations in molecular clouds, intermediate in revealed stellar clusters, and oldest in distributed populations. The NIR color index J-H, a surrogate measure of extinction, can serve as an approximate age predictor for young embedded clusters.2014ApJ...787..108Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/787/108CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJS/209/27 : MYStIX: the Chandra X-ray sources (Kuhn+, 2013)J/ApJS/209/28 : MYStIX Wide-Field NIR data: crowded fields (King+, 2013)J/ApJS/209/31 : The MYStIX IR-Excess Source catalog (MIRES) (Povich+, 2013)J/ApJS/209/32 : Probable young stars in the MYStIX project (Broos+, 2013)J/ApJ/787/107 : Spatial structure of young stellar clusters. I. (Kuhn+, 2014)J/ApJ/787/109 : Age estimates for NGC 2024 and ONC stars (Getman+, 2014)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/787/108https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/787/108http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/787/108https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/787/108https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/787/108http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/787/108GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/787/108/table1 (Individual Stellar Age Estimates)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/787/108/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/787/108/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/787/108/table1?GETtext/xml+votable180.050000true83.62272611-5.393730.005555555555555556Cone search capability for table J/ApJ/787/108/table2 (Age Estimates for the MYStIX Clusters)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/787/108/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/787/108/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/787/108/table2?GETtext/xml+votable180.050000true83.81100306-5.375278060.0055555555555555565/10615 6/1285 1287 1298 3307 3649 14682 14704 21438 21439 22243 22249 22804 22805 22855 23637 23639 28890 28891 28913 29116 29118 29463 29504 29506 30341 37333 37872 37884 37886 37923 38016 39907 42456 42457 424581.1166583743361574e-19 1.7003137259100215e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/787/108?format=asciiX-rayOpticalInfrareddefaultJ/ApJ/787/108/table1Individual Stellar Age EstimatesMemCluster membership code (G1)meta.codecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRegionStar formation regionphys.SFR;obs.fieldcharNameMYStIX IAU source identifier (HHMMSS.ss+DDMMSS.s)meta.id;meta.maincharRAJ2000Right Ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainJmag2MASS J band magnitude (1)magphot.mag;em.IR.Jfloate_JmagUncertainty in Jmagmagstat.error;phot.mag;em.IR.JfloatHmag2MASS H band magnitude (1)magphot.mag;em.IR.Hfloate_HmagUncertainty in Hmagmagstat.error;phot.mag;em.IR.HfloatKsmag2MASS K_s_ band magnitude (1)magphot.mag;em.IR.Kfloate_KsmagUncertainty in Ksmagmagstat.error;phot.mag;em.IR.KfloatLXIntrinsic 0.5-8 keV band X-ray luminosity; 10^30^ erg/s (1)1e+23Wphys.luminosity;em.X-rayfloate_LXUncertainty in LX (2)1e+23Wstat.errorfloatAJJ band extinction estimatemagphys.absorption;em.IR.JfloatAgeJXThe Age_JX_ estimate (3)Myrtime.agefloatJ/ApJ/787/108/table2Age Estimates for the MYStIX ClustersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRegionStar formation regionphys.SFR;obs.fieldcharMemCluster membership code (G1)meta.codecharRAJ2000? Right Ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainnullableDEJ2000? Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainnullableR? Spatial extent of a MYStIX cluster (1)arcminphys.angSizefloatnullableRpc? Spatial extent of a MYStIX cluster (2)pcphys.angSizefloatnullableNtotTotal number of MYStIX stars assigned as cluster membermeta.numberintNtotm? MYStIX stars median J-H color (Kuhn et al. 2014, J/ApJ/787/107)magphot.color;em.IR.J;em.IR.HfloatnullableNAgeJX? Number of AgeJX stars assigned as cluster membermeta.numberintnullableNAgeJXm? AgeJX stars median J-H colormagphot.color;em.IR.J;em.IR.Hfloatnullablee_NAgeJXm? Uncertainty in NAgeJXmmagstat.errorfloatnullableAgeJXm? Cluster median(AgeJX) estimateMyrtime.agefloatnullablee_AgeJXm? Uncertainty in AgeJXmMyrstat.errorfloatnullableAgeJH? Independent age estimate (3)Myrtime.agefloatnullableu_AgeJH[:] Uncertainty flag on AgeJHmeta.code.errorchar