J/ApJ/602/850ivo://CDS.VizieR/J/ApJ/602/850doi:10.26093/cds/vizier.16020850CDSShepherd D.S.Nurnberger D.E.A.Bronfman L.2005-10-22T07:13:26Z2005-10-22T07:12:14ZCDS support team

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

cds-question@unistra.frradio-sourcesh-ii-regionspre-main-sequence-starsinfrared-photometryWe have observed the massive star-forming region IRAS 18507+0121 at millimeter wavelengths in 3mm continuum emission, H^13^CO+ (J=1-0) and SiO (v=0,J=2-1) line emission, and at near-infrared (NIR) wavelengths between 1.2 and 2.1{mu}m. Two compact molecular cores are detected: one north and one south, separated by ~40". The northern molecular core contains a newly discovered, deeply embedded, B2 protostar surrounded by several hundred solar masses of warm gas and dust, G34.4+0.23 MM. Based on the presence of warm dust emission and the lack of detection at NIR wavelengths, we suggest that G34.4+0.23 MM may represent the relatively rare discovery of a massive protostar (e.g., analogous to a low-mass "Class 0" protostar). The southern molecular core is associated with an NIR cluster of young stars and an ultracompact HII region, G34.4+0.23, with a central B0.5 star. The fraction of NIR stars with excess infrared emission indicative of circumstellar material is greater than 50%, which suggests an upper limit on the age of the IRAS 18507+0121 star-forming region of 3Myr.2004ApJ...602..850Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/602/850CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/602/850https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/602/850http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/602/850https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/602/850https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/602/850http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/602/850GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/602/850/table1 (Positions and JHK' photometry of all detected sources)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/602/850/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/602/850/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/602/850/table1?GETtext/xml+votable180.050000true283.32283331.40502780.0055555555555555566/30318https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/602/850?format=asciiInfraredRadiodefaultJ/ApJ/602/850/table1Positions and JHK' photometry of all detected sourcesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint[SNB2004]Source number (1)intDelXThe X position offset (2)arcsecfloatDelYThe Y position offset (2)arcsecfloatRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainJmag? The J band magnitude (3)magfloatnullableHmag? The H band magnitude (3)magfloatnullablel_K'magLimit flag on KcharK'mag? The K' band magnitude (3)magfloatnullable