J/MNRAS/461/4022ivo://CDS.VizieR/J/MNRAS/461/4022doi:10.26093/cds/vizier.74614022CDSMairs S.Johnstone D.Kirk H.Buckle J.Berry D.S.,Broekhoven-Fiene H.Currie M.J.Fich M.Graves S.Hatchell J.,Jenness T.Mottram J.C.Nutter D.Pattle K.Pineda J.E.Salji C.,Di Francesco J.Hogerheijde M.R.Ward-Thompson D.Bastien P.,Bresnahan D.Butner H.Chen M.Chrysostomou A.Coude S.Davis C.J.,Drabek-Maunder E.Duarte-Cabral A.Fiege J.Friberg P.Friesen R.,Fuller G.A.Greaves J.Gregson J.Holland W.Joncas G.Kirk J.M.,Knee L.B.G.Marsh K.Matthews B.C.Moriarty-Schieven G.Mowat C.,Rawlings J.Richer J.Robertson D.Rosolowsky E.Rumble D.Sadavoy S.,Thomas H.Tothill N.Viti S.White G.J.Wouterloot J.Yates J.Zhu M.2024-08-16T20:17:58Z2018-01-18T14:29:27ZCDS support team

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

cds-question@unistra.frmolecular-cloudsmillimeter-astronomysubmillimeter-astronomyWe present the JCMT Gould Belt Survey's first look results of the southern extent of the Orion A Molecular Cloud ({delta}<=-5:31:27.5). Employing a two-step structure identification process, we construct individual catalogues for large-scale regions of significant emission labelled as islands and smaller-scale subregions called fragments using the 850{mu}m continuum maps obtained using SCUBA-2. We calculate object masses, sizes, column densities, and concentrations. We discuss fragmentation in terms of a Jeans instability analysis and highlight interesting structures as candidates for follow-up studies. Furthermore, we associate the detected emission with young stellar objects (YSOs) identified by Spitzer and Herschel. We find that although the population of active star-forming regions contains a wide variety of sizes and morphologies, there is a strong positive correlation between the concentration of an emission region and its calculated Jeans instability. There are, however, a number of highly unstable subregions in dense areas of the map that show no evidence of star formation. We find that only ~72 per cent of the YSOs defined as Class 0+I and flat-spectrum protostars coincide with dense 850{mu}m emission structures (column densities >3.7x10^21^cm^-2^). The remaining 28 per cent of these objects, which are expected to be embedded in dust and gas, may be misclassified. Finally, we suggest that there is an evolution in the velocity dispersion of YSOs such that sources which are more evolved are associated with higher velocities.2016MNRAS.461.4022Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/461/4022CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVIII/12 : Orion A Emission-Line Surveys (Jewell+ 1989)J/A+A/392/239 : IR survey of outflows in Orion A (Stanke+, 2002)J/ApJ/653/383 : SCUBA obs. in Orion A South region (Johnstone+, 2006)J/ApJ/665/1194 : Dense cores in the Orion A cloud survey (Ikeda+, 2007)J/A+A/496/153 : Molecular hydrogen flows along Ori A cloud (Davis+, 2009)J/AJ/144/192 : Spitzer survey of Orion A & B. YSO catalog (Megeath+, 2012)J/A+A/564/A29 : Optical and near-infrared phot. in Orion A (Bouy+, 2014)J/A+A/564/A68 : Orion A GMC 13CO and C18O maps (Shimajiri+, 2014)J/ApJ/764/114 : BVRI photometry of stars in Orion A (Hsu+, 2013)J/ApJ/768/99 : X-ray survey of YSOs in Orion A (Pillitteri+, 2013)J/ApJ/769/149 : IR spectroscopy in Orion A: transitional disks (Kim+, 2013)J/ApJ/790/49 : Gould's Belt VLA survey. III. Orion region (Kounkel+, 2014)J/ApJS/217/7 : Orion A dense cores based on 1.1mm and C^18^OJ/MNRAS/449/1769 : Orion A North prestellar core properties (Salji+, 2015)J/A+A/587/A153 : VISION I. VISTA Orion A Survey (Meingast+, 2016)J/ApJS/226/8 : Orion A Class II objects Spitzer/IRS survey (Kim+, 2016)J/A+A/600/A141 : Orion A integral shaped filament image (Kainulainen+, 2017)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/461/4022https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/461/4022http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/461/4022https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/461/4022https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/461/4022http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/461/4022GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/461/4022/table2 (Observed parameters corresponding to the 850um-identified islands)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/461/4022/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/461/4022/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/461/4022/table2?GETtext/xml+votable180.050000true84.079125-6.36996670.005555555555555556Cone search capability for table J/MNRAS/461/4022/table4 (850um-identified fragments and their properties)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/461/4022/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/461/4022/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/461/4022/table4?GETtext/xml+votable180.050000true84.079125-6.36996670.0055555555555555566/21402-21403 21425 21427-21428 21430 21433 21436 21438-21439 228042.3390025583187276e-22 4.414320791325542e-22https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/461/4022?format=asciiRadiodefaultJ/MNRAS/461/4022/table2Observed parameters corresponding to the 850um-identified islandsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJLSGSource name (JHHMMSS.s+DDMMSSI) (1)meta.id;meta.maincharIslandID[1/359] Island identification numbermeta.idintRAJ2000Right ascension (J2000) (2)pos.eq.ra;meta.mainDEJ2000Declination (J2000) (2)pos.eq.dec;meta.mainAreaTotal area of an islandarcsec**2phys.areadoubleS850Total 850um flux observed within the island's boundariesJyphot.flux.density;em.mm.200-400GHzfloatF850peakMaximum 850um flux value within the island's boundariesJy/beamphot.flux.density;em.mm.200-400GHz;stat.maxfloatS450Total 450um flux observed within the island's boundariesJyphot.flux.density;em.mm.400-750GHzfloatF450peakMaximum 450um flux value within the island's boundariesJy/beamphot.flux.density;em.mm.400-750GHz;stat.maxfloatJ/MNRAS/461/4022/table3850um-identified islands and their propertiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIslandID[1/359] Island identification numbermeta.idintNpeakPeak column density (1)cm**-2phys.columnDensity;stat.maxdoubleMassMass (2)solMassphys.massfloatRadEffective radius (3)pcphys.size.radiusfloatM/MJMass in Jeans mass unit (4)phys.mass;arith.ratiofloatCConcentration (calculated using equation (4))meta.notefloatARAspect ratio of the source (5)src.morph.paramfloatAkAverage K-band extinction value (6)magphys.absorptionfloatNfragsNumber of fragments associated with the islandmeta.numberintNprotoNumber of protostars identified by Megeath et al. (2012, Cat. J/AJ/144/192) and Stutz et al. (2013, Cat. J/ApJ/767/36) within the island's boundariesmeta.numberintJ/MNRAS/461/4022/table4850um-identified fragments and their propertiesDEJ2000Declination (J2000) (2)pos.eq.dec;meta.mainNpeakPeak column density (3)cm**-2phys.columnDensity;stat.maxdoublerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJLSGSource name (JHHMMSS.s+DDMMSSF) (1)meta.id;meta.maincharFragID[1/431] Fragment identification numbermeta.idintIslandID[1/356]? Island numbermeta.idintnullableRAJ2000Right ascension (J2000) (2)pos.eq.ra;meta.mainMassMass (4)solMassphys.massfloatRadEffective radius (5)pcphys.size.radiusfloatM/MJMass in Jeans mass unit (6)phys.mass;arith.ratiofloatCConcentration (calculated using equation (4))meta.notefloatARAspect ratio of the source (7)src.morph.paramfloatAkAverage K-band extinction value (8)magphys.absorptionfloatNprotoNumber of protostars identified by Megeath et al. (2012, Cat. J/AJ/144/192) and Stutz et al. (2013, Cat. J/ApJ/767/36) within the fragment's boundariesmeta.numberint