J/A+A/599/A37ivo://CDS.VizieR/J/A+A/599/A37doi:10.26093/cds/vizier.35990037CDSDjupvik A.A.Comeron F.Schneider N.2019-05-02T09:24:02Z2017-02-24T08:12:57ZCDS support team

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

cds-question@unistra.frinfrared-sourcesinterstellar-cloudsyoung-stellar-objectsinfrared-photometryvisible-astronomyphotometrymillimeter-astronomysubmillimeter-astronomyGlobules and pillars, impressively revealed by the Spitzer and Herschel satellites, for example, are pervasive features found in regions of massive star formation. Studying their embedded stellar populations can provide an excellent laboratory to test theories of triggered star formation and the features that it may imprint on the stellar aggregates resulting from it. We studied the globule IRAS 20319+3958 in Cygnus X by means of visible and near-infrared imaging and spectroscopy, complemented with mid-infrared Spitzer/IRAC imaging, in order to obtain a census of its stellar content and the nature of its embedded sources. Our observations show that the globule contains an embedded aggregate of about 30 very young (<~1Myr) stellar objects, for which we estimate a total mass of ~90M_{sun}_. The most massive members are three systems containing early B-type stars. Two of them most likely produced very compact HII regions, one of them being still highly embedded and coinciding with a peak seen in emission lines characterising the photon dominated region (PDR). Two of these three systems are resolved binaries, and one of those contains a visible Herbig Be star. An approximate derivation of the mass function of the members of the aggregate gives hints of a slope at high masses shallower than the classical Salpeter slope, and a peak of the mass distribution at a mass higher than that at which the widely adopted log-normal initial mass function peaks. The emission distribution of H_2_ and Brackett gamma, tracing the PDR and the ionised gas phase, respectively, suggests that molecular gas is distributed as a shell around the embedded aggregate, filled with centrally-condensed ionised gas. Both, the morphology and the low excitation of the HII region, indicate that the sources of ionisation are the B stars of the embedded aggregate, rather than the external UV field caused by the O stars of Cygnus OB2. The youth of the embedded cluster, combined with the isolation of the globule, suggests that star formation in the globule was triggered by the passage of the ionisation front.2017A&A...599A..37Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/599/A37CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/150/191 : IR photometry of YSOs in Cygnus-X DR15 (Rivera-Galvez+, 2015)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/599/A37https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/599/A37http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/599/A37https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/599/A37https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/599/A37http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/599/A37GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/599/A37/table3 (YSO candidates)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/599/A37/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/599/A37/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/599/A37/table3?GETtext/xml+votable180.050000true308.303710940.09212880.0055555555555555566/146707.952274030004205e-20 3.852589004194616e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/599/A37?format=asciiOpticalInfraredMillimeterdefaultJ/A+A/599/A37/table3YSO candidatesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/144] Identification numbermeta.id;meta.mainintRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainl_VmagUpper limit flag on Vmagmeta.code.errorcharVmag? CAMELOT/IAC80 V-band magnitudemagphot.mag;em.opt.Vfloatnullablee_Vmag? Error in Vmagmagstat.error;phot.mag;em.opt.Vfloatnullablel_RmagUpper limit flag on Rmagmeta.code.errorcharRmag? CAMELOT/IAC80 R-band magnitudemagphot.mag;em.opt.Rfloatnullablee_Rmag? Error in Rmagmagstat.error;phot.mag;em.opt.RfloatnullableImag? CAMELOT/IAC80 I-band magnitudemagphot.mag;em.opt.Ifloatnullablee_Imag? Error in Imagmagstat.error;phot.mag;em.opt.Ifloatnullablel_JmagUpper limit flag on Jmagmeta.code.errorcharJmagOmega2000/3.5m J-band magnitudemagphot.mag;em.IR.Jfloate_Jmag? Error in Jmagmagstat.error;phot.mag;em.IR.JfloatnullableHmagOmega2000/3.5m H-band magnitudemagphot.mag;em.IR.Hfloate_HmagError in Hmagmagstat.error;phot.mag;em.IR.HfloatKsmagOmega2000/3.5m Ks-band magnitudemagphot.mag;em.IR.Kfloate_KsmagError in Ksmagmagstat.error;phot.mag;em.IR.Kfloatl_[3.6]Upper limit flag on [3.6]meta.code.errorchar[3.6]? IRAC [3.6] magnitudemagphot.mag;em.IR.3-4umfloatnullablee_[3.6]? Error in [3.6]magstat.errorfloatnullablel_[4.5]Upper limit flag on [4.5]meta.code.errorchar[4.5]? IRAC [4.5] magnitudemagphot.mag;em.IR.4-8umfloatnullablee_[4.5]? Error in [4.5]magstat.errorfloatnullablel_[5.8]Upper limit flag on [5.8]meta.code.errorchar[5.8]? IRAC [5.8] magnitudemagphot.flux.density;em.IR.4-8umfloatnullablee_[5.8]? Error in [5.8]magstat.errorfloatnullablel_[8.0]Upper limit flag on [8.0]meta.code.errorchar[8.0]? IRAC [8.0] magnitudemagphot.flux.density;em.IR.8-15umfloatnullablee_[8.0]? Error in [8.0]magstat.errorfloatnullablefYSO[1/5] YSO type/selection criteria (1)meta.codeintNameOther name used in this papermeta.idcharfPhot[abcde ,] Photometric flag(s) (2)meta.codecharSimbadSimbad column added by the CDSmeta.ref.urlchar