J/ApJ/802/60ivo://CDS.VizieR/J/ApJ/802/60doi:10.26093/cds/vizier.18020060CDSKuhn M.A.Getman K.V.Feigelson E.D.2015-09-17T15:56:39Z2015-08-27T07:59:27ZCDS support team

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

cds-question@unistra.fryoung-stellar-objectsstellar-associationsmolecular-cloudsh-ii-regionsWe investigate the intrinsic stellar populations (estimated total numbers of OB and pre-main-sequence stars down to 0.1M_{sun}_) that are present in 17 massive star-forming regions (MSFRs) surveyed by the MYStIX project. The study is based on the catalog of >31000 MYStIX Probable Complex Members with both disk-bearing and disk-free populations, compensating for extinction, nebulosity, and crowding effects. Correction for observational sensitivities is made using the X-ray luminosity function and the near-infrared initial mass function --a correction that is often not made by infrared surveys of young stars. The resulting maps of the projected structure of the young stellar populations, in units of intrinsic stellar surface density, allow direct comparison between different regions. Several regions have multiple dense clumps, similar in size and density to the Orion Nebula Cluster. The highest projected density of ~34000 stars/pc2 is found in the core of the RCW 38 cluster. Histograms of surface density show different ranges of values in different regions, supporting the conclusion of Bressert et al. (B10; 2010MNRAS.409L..54B) that no universal surface-density threshold can distinguish between clustered and distributed star formation. However, a large component of the young stellar population of MSFRs resides in dense environments of 200-10000 stars/pc2 (including within the nearby Orion molecular clouds), and we find that there is no evidence for the B10 conclusion that such dense regions form an extreme "tail" of the distribution. Tables of intrinsic populations for these regions are used in our companion study of young cluster properties and evolution.2015ApJ...802...60Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/802/60CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/apJ/787/107 : Spatial structure of young stellar clusters. I. (Kuhn+, 2014)J/ApJS/213/1 : The MSFRs Omnibus X-ray Catalog (MOXC) (Townsley+, 2014)J/other/JApA/34.393 : X-rays obs. in 8 young open star clusters (Bhatt+, 2013)J/ApJS/209/32 : Probable young stars in the MYStIX project (Broos+, 2013)J/ApJS/209/31 : The MYStIX IR-Excess Source catalog (MIRES) (Povich+, 2013)J/ApJS/209/30 : MYStIX project: Bayesian matching (Naylor+, 2013)J/ApJS/209/29 : MYStIX: Mid-IR observations and catalogs (Kuhn+, 2013)J/ApJS/209/28 : MYStIX Wide-Field NIR data: crowded fields (King+, 2013)J/ApJS/209/27 : MYStIX: the Chandra X-ray sources (Kuhn+, 2013)J/ApJ/768/99 : X-ray survey of YSOs in Orion A (Pillitteri+, 2013)J/AJ/144/192 : Spitzer survey of Orion A & B. I. YSO catalog (Megeath+, 2012)J/MNRAS/426/2917 : X-rays sources in Trumpler 37 (Getman+, 2012)J/A+A/539/A74 : NGC1893 Chandra X-ray catalog (Caramazza+, 2012)J/A+A/533/A121 : Missing low-mass stars in S254-S258 (Mucciarelli+, 2011)J/ApJS/194/14 : A Pan-Carina YSO catalog (Povich+, 2011)J/ApJS/194/12 : Trumpler 16 in the CCCP (Wolk+, 2011)J/ApJS/194/11 : Chandra study of Trumpler 15 in Carina (Wang+, 2011)J/ApJS/194/9 : X-ray star clusters in the Carina complex (Feigelson+, 2011)J/ApJS/194/2 : Chandra Carina Complex Project (CCCP) catalog (Broos+, 2011)J/ApJ/725/2485 : X-rays from the star-forming complex W40 (Kuhn+, 2010)J/ApJ/716/474 : The Rosette star-forming complex. III. (Wang+, 2010)J/ApJ/713/871 : Star-forming region Cyg-OB2 sources from X-ray (Wright+, 2010)J/ApJS/186/259 : Taurus Spitzer survey: new candidate members (Rebull+, 2010)J/ApJ/708/1760 : Flux estimations of faint X-ray sources (Getman+, 2010)J/ApJS/184/18 : Spitzer survey of young stellar clusters (Gutermuth+, 2009)J/AJ/138/227 : Stellar clusters in NGC 6334 complex (Feigelson+, 2009)J/ApJ/696/47 : Rosette star-forming complex with Chandra. II. (Wang+, 2009)J/ApJ/677/401 : Xray properties of protostars in ONC (Prisinzano+, 2008)J/ApJS/169/353 : Chandra sources in M17 (Broos+, 2007)J/ApJS/168/100 : X-ray study of star-forming region NGC 6357 (Wang+, 2007)J/ApJS/160/353 : Membership of the Orion nebula population (Getman+, 2005)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/802/60https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/802/60http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/802/60https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/802/60https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/802/60http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/802/60GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/802/60/table2 (Intrinsic population estimates from the X-ray luminosity function (XLF) and initial mass function (IMF))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/802/60/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/802/60/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/802/60/table2?GETtext/xml+votable180.050000true83.811003-5.37527770.005555555555555556Cone search capability for table J/ApJ/802/60/fits (Massive star-forming regions (MSFRs) FITS images summary)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/802/60/fits?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/802/60/fits?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/802/60/fits?GETtext/xml+votable180.050000true83.81702-5.404540.005555555555555556Associated datahttps://cdsarc.cds.unistra.fr/assocdata/?obs_collection=J/ApJ/802/606/1287 14682 14704 21439 22243 22249 22855 23637 28890 28891 28913 29116 29118 29463 29504 29506 30341 37872 37884 38016 39907 42456 42457 42458 42460 42462https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/802/60?format=asciiOpticaldefaultJ/ApJ/802/60/table2Intrinsic population estimates from the X-ray luminosity function (XLF) and initial mass function (IMF)MSFRMYStIX region namemeta.id;obs.fieldcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintm_MSFRSubcluster designation as in Paper I (Kuhn+, 2014, J/ApJ/787/107)meta.code.multipcharRAJ2000Right ascension in decimal degrees (J2000) (1)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000) (1)degpos.eq.dec;meta.mainamaj[0.07/61] Semimajor axis of subcluster; 4x core ellipsearcminphys.angSize;srcfloatbmin[0.07/13.1] Semiminor axis of subcluster; 4x core ellipsearcminphys.angSize.sminAxisfloatPAPosition angle of the subcluster; East from Northdegpos.posAngintNxlf[0.9/3.7]? Log intrinsic number of stars inferred via XLF (2)meta.numberfloatnullablee_Nxlf? Uncertainty on Nxlf (3)stat.errorfloatnullableNimf[0.5/3.6]? Log intrinsic number of stars inferred via initial mass function (IMF) (2)meta.numberfloatnullablee_Nimf? Uncertainty on Nimf (3)stat.errorfloatnullablePapIDisplay sub-cluster properties from Paper I (Kuhn et al. 2014, J/ApJ/787/107) for this subclustermeta.ref.urlcharJ/ApJ/802/60/fitsMassive star-forming regions (MSFRs) FITS images summaryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHDU[1/17] HDU "IMAGE" extension numbermeta.idintNameMYStIX region namemeta.id;obs.fieldcharNx[512] Number of pixels along X-axis (RA)meta.numberintNy[362/815] Number of pixels along Y-axis (DE)meta.numberintRAJ2000Right ascension of center (J2000)degpos.eq.ra;meta.mainDEJ2000Declination of center (J2000)degpos.eq.dec;meta.mainScale[0.9/7.5] Scale of the imagearcsec/pixinstr.scalefloatFileName1FITS file of Fig.3 in subdirectory fits (1)meta.notecharFileName2FITS file of Fig.5 in subdirectory fits (2)meta.notechar