J/ApJ/752/59ivo://CDS.VizieR/J/ApJ/752/59doi:10.26093/cds/vizier.17520059CDSHsu W.-H.Hartmann L.Allen L.Hernandez J.Megeath S.T.Mosby G.,Tobin J.J.Espaillat C.2017-06-20T13:17:27Z2014-02-24T15:27:18ZCDS support team

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

cds-question@unistra.frline-intensitiesstellar-spectral-typesinfrared-photometryvisible-astronomyphotometryyoung-stellar-objectsWe present results from an optical photometric and spectroscopic survey of the young stellar population in L1641, the low-density star-forming region of the Orion A cloud south of the Orion Nebula Cluster (ONC). Our goal is to determine whether L1641 has a large enough low-mass population to make the known lack of high-mass stars a statistically significant demonstration of environmental dependence of the upper mass stellar initial mass function (IMF). Our spectroscopic sample consists of IR-excess objects selected from the Spitzer/IRAC survey and non-excess objects selected from optical photometry. We have spectral confirmation of 864 members, with another 98 probable members; of the confirmed members, 406 have infrared excesses and 458 do not. Assuming the same ratio of stars with and without IR excesses in the highly extincted regions, L1641 may contain as many as ~1600 stars down to ~0.1M_{sun}_, comparable within a factor of two to the ONC. Compared to the standard models of the IMF, L1641 is deficient in O and early B stars to a 3{sigma}-4{sigma} significance level, assuming that we know of all the massive stars in L1641.2012ApJ...752...59Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/752/59CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)J/ApJS/207/5 : YSOs in LDN 1641 with Hectochelle spectra (Fang+, 2013)J/ApJ/722/1092 : Optical photometry of the ONC. II. (Da Rio+, 2010)J/AJ/139/950 : JHKs photometry in ONC (Robberto+, 2010)J/ApJS/184/18 : Spitzer survey of young stellar clusters (Gutermuth+, 2009)J/A+A/504/461 : YSOs in L1630N and L1641 (Fang+, 2009)J/A+A/489/1409 : IR photometry and spectroscopy in L1641N (Galfalk+, 2008)J/A+A/337/403 : Low-mass stars evolutionary models (Baraffe+ 1998)J/AJ/113/1733 : Orion Nebula Cluster population (Hillenbrand 1997)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/752/59https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/752/59http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/752/59https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/752/59https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/752/59http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/752/59GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/752/59/members (Confirmed or probable members in L1641)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/752/59/members?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/752/59/members?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/752/59/members?GETtext/xml+votable180.050000true83.21121-6.185930.005555555555555556Cone search capability for table J/ApJ/752/59/table4 (YSOs with strong emission lines)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/752/59/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/752/59/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/752/59/table4?GETtext/xml+votable180.050000true83.30896-6.196890.0055555555555555566/21403 21406 21425 21427 21428 21430 21433 21435 21436 214388.650015785639275e-20 3.852589004194616e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/752/59?format=asciiOpticalInfrareddefaultJ/ApJ/752/59/membersConfirmed or probable members in L1641SimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMmSimbad column added by the CDSmeta.code.membercharSeqRunning sequence numbermeta.id;meta.mainintRAJ2000Right Ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainVmag[12/23]? V band magnitudemagphot.mag;em.opt.VdoublenullableImag[11/20]? I band magnitudemagphot.mag;em.opt.IdoublenullableJmag[9/18]? 2MASS J band magnitudemagphot.mag;em.IR.JdoublenullableHmag[8/17]? 2MASS H band magnitudemagphot.mag;em.IR.HdoublenullableKmag[7/17]? 2MASS Ks band magnitudemagphot.mag;em.IR.KdoublenullableSpTMK spectral typesrc.spTypechare_SpT? Uncertainty in SpTstat.errorfloatnullabler_SpTOrigin of SpT (1)meta.ref;pos.framecharIR[Y/N] IR excess? (2)meta.codecharEWHaH{alpha} equivalent width0.1nmspect.line.eqWidth;em.line.HalphafloatEWLi? Lithium equivalent width0.1nmspect.line.eqWidthfloatnullableDate? Date of the observation (3)time.epochnullableF09Cross-match with Fang+, 2009, Cat. J/A+A/504/461, within 1.5"meta.ref.urlintnullable2MDisplay the 2MASS data (Cutri et al. 2003, Cat. II/246) within 1"meta.ref.urlcharJ/ApJ/752/59/table4YSOs with strong emission linesSeq[6/861] Running sequence numbermeta.id;meta.mainintW7773? Equivalent width of [OI] 7773{AA}0.1nmspect.line.eqWidthfloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right Ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainW5577? Equivalent width of [OI] 5577{AA}0.1nmspect.line.eqWidthfloatnullableW6300? Equivalent width of [OI] 6300{AA}0.1nmspect.line.eqWidthfloatnullableW6363? Equivalent width of [OI] 6363{AA}0.1nmspect.line.eqWidthfloatnullableW6538? Equivalent width of [NII] 6548{AA}0.1nmspect.line.eqWidthfloatnullableW6583? Equivalent width of [NII] 6583{AA}0.1nmspect.line.eqWidthfloatnullableW6678? Equivalent width of HeI 6678{AA}0.1nmspect.line.eqWidthfloatnullableW6716? Equivalent width of [SII] 6716{AA}0.1nmspect.line.eqWidthfloatnullableW6731? Equivalent width of [SII] 6731{AA}0.1nmspect.line.eqWidthfloatnullableW8446? Equivalent width of [OI] 8446{AA}0.1nmspect.line.eqWidthfloatnullableW8498? Equivalent width of [CaII] 8498{AA}0.1nmspect.line.eqWidthfloatnullableW8542? Equivalent width of [CaII] 8542{AA}0.1nmspect.line.eqWidthfloatnullableW8662? Equivalent width of [CaII] 8662{AA}0.1nmspect.line.eqWidthfloatnullable