J/ApJ/821/52ivo://CDS.VizieR/J/ApJ/821/52doi:10.26093/cds/vizier.18210052CDSKounkel M.Megeath S.T.Poteet C.A.Fischer W.J.Hartmann L.2018-05-29T11:44:08Z2016-07-22T09:57:10ZCDS support team

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

cds-question@unistra.fryoung-stellar-objectsinfrared-photometrymultiple-starshst-photometrysurveysWe present a near-infrared survey for the visual multiples in the Orion molecular clouds region at separations between 100 and 1000au. These data were acquired at 1.6um with the NICMOS and WFC3 cameras on the Hubble Space Telescope. Additional photometry was obtained for some of the sources at 2.05um with NICMOS and in the L' band with NSFCAM2 on NASA's InfraRed Telescope Facility. Toward 129 protostars and 197 pre-main-sequence stars with disks observed with WFC3, we detect 21 and 28 candidate companions between the projected separations of 100-1000au, of which less than 5 and 8, respectively, are chance line-of-sight coincidences. The resulting companion fraction (CF) after the correction for the line-of-sight contamination is 14.4_-1.3_^+1.1^ for protostars and 12.5_-0.8_^+1.2^ for the pre-main-sequence stars. These values are similar to those found for main-sequence stars, suggesting that there is little variation in the CF with evolution, although several observational biases may mask a decrease in the CF from protostars to the main-sequence stars. After segregating the sample into two populations based on the surrounding surface density of young stellar objects, we find that the CF in the high stellar density regions ({Sigma}_YSO_>45pc^-2^) is approximately 50% higher than that found in the low stellar density regions ({Sigma}_YSO_<45pc^-2^). We interpret this as evidence for the elevated formation of companions at 100-1000 au in the denser environments of Orion. We discuss possible reasons for this elevated formation.2016ApJ...821...52Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/821/52CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJS/224/5 : Herschel Orion Protostar Survey (HOPS): SEDs (Furlan+, 2016)J/ApJ/818/59 : IN-SYNC. IV. YSOs in Orion A (Da Rio+, 2016)J/ApJ/767/36 : APEX observations of HOPS protostars (Stutz+, 2013)J/AJ/144/192 : Spitzer survey of Orion A & B. I. YSO catalog (Megeath+, 2012)J/AJ/144/31 : Spitzer+2MASS photom. of protostar candidates (Kryukova+, 2012)J/ApJ/731/8 : Multiple star formation in Taurus-Auriga (Kraus+, 2011)J/ApJS/184/18 : Spitzer survey of young stellar clusters (Gutermuth+, 2009)J/AJ/135/2496 : Near-IR survey of Class I protostars (Connelley+, 2008)J/AJ/134/2272 : Visual binaries in the Orion Nebula Cluster (Reipurth+, 2007)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/821/52https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/821/52http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/821/52https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/821/52https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/821/52http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/821/52GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/821/52/table1 (List of the candidate multiple systems with projected separations less than 1000AU)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/821/52/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/821/52/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/821/52/table1?GETtext/xml+votable180.050000true88.73729171.71558330.005555555555555556Cone search capability for table J/ApJ/821/52/table2 (List of the YSOs without a companion)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/821/52/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/821/52/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/821/52/table2?GETtext/xml+votable180.050000true88.55145831.70976110.0055555555555555566/21403 21425 21427 21428 21430 21435 21436 21438 21439 22805 22854 22855 22873 22876 235604.925240337479573e-20 1.4053184620945436e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/821/52?format=asciiInfrareddefaultJ/ApJ/821/52/table1List of the candidate multiple systems with projected separations less than 1000AUSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTypeSource type (0=protostars, 1=stars with disks)meta.code.classcharNameSource identifier (2)meta.id;meta.maincharRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainWF160W[8.2/23.2]? HST/WFC3 F160W band magnitudemagphot.mag;em.IR.Hfloatnullablee_WF160W[0.01/0.3]? Uncertainty in WF160Wmagmagstat.errorfloatnullableNF160W[8.8/20.8]? HST/NICMOS F160W band magnitudemagphot.mag;em.IR.Hfloatnullablee_NF160W[0.001/0.09]? Uncertainty in NF160Wmagmagstat.errorfloatnullableNF205W[8.2/22]? HST/NICMOS F205W band magnitudemagphot.mag;em.IR.Kfloatnullablee_NF205W[0.001/0.4]? Uncertainty in NF205Wmagmagstat.errorfloatnullableLmag[5.1/14.5]? IRTF/NSFCAM2 L' (3.76um) band magnitudemagphot.mag;em.IR.3-4umfloatnullablee_Lmag[0/0.5]? Uncertainty in Lmagmagstat.error;phot.mag;em.IR.3-4umfloatnullableSep[80/997]? Projected separation (only for table 1)AUpos.angDistanceintnullableCNameCommon identifiermeta.idcharM12Display data from Megeath+, 2012, J/AJ/144/192 and Kryukova+, 2012, J/AJ/144/31, within 1"meta.ref.urlintnullableHOPSDisplay the HOPS data from Furlan+ 2016, J/ApJS/224/5, within 2"meta.ref.urlintnullable2MDisplay the 2MASS data (Cutri+ 2003, II/246) within 2"meta.ref.urlintnullableJ/ApJ/821/52/table2List of the YSOs without a companionSimbadNameSimbad column added by the CDSmeta.idcharCNameCommon identifiermeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTypeSource type (0=protostars, 1=stars with disks)meta.code.classcharNameSource identifier (2)meta.id;meta.maincharRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainWF160W[8.2/23.2]? HST/WFC3 F160W band magnitudemagphot.mag;em.IR.Hfloatnullablee_WF160W[0.01/0.3]? Uncertainty in WF160Wmagmagstat.errorfloatnullableNF160W[8.8/20.8]? HST/NICMOS F160W band magnitudemagphot.mag;em.IR.Hfloatnullablee_NF160W[0.001/0.09]? Uncertainty in NF160Wmagmagstat.errorfloatnullableNF205W[8.2/22]? HST/NICMOS F205W band magnitudemagphot.mag;em.IR.Kfloatnullablee_NF205W[0.001/0.4]? Uncertainty in NF205Wmagmagstat.errorfloatnullableLmag[5.1/14.5]? IRTF/NSFCAM2 L' (3.76um) band magnitudemagphot.mag;em.IR.3-4umfloatnullablee_Lmag[0/0.5]? Uncertainty in Lmagmagstat.error;phot.mag;em.IR.3-4umfloatnullableM12Display data from Megeath+, 2012, J/AJ/144/192 and Kryukova+, 2012, J/AJ/144/31, within 1"meta.ref.urlintnullableHOPSDisplay the HOPS data from Furlan+ 2016, J/ApJS/224/5, within 2"meta.ref.urlintnullable2MDisplay the 2MASS data (Cutri+ 2003, II/246) within 2"meta.ref.urlintnullable