J/ApJS/226/8ivo://CDS.VizieR/J/ApJS/226/8doi:10.26093/cds/vizier.22260008CDSKim K.H.Watson D.M.Manoj P.Forrest W.J.Furlan E.Najita J.,Sargent B.Hernandez J.Calvet N.Adame L.Espaillat C.Megeath S.T.,Muzerolle J.McClure M.K.2017-06-22T14:28:42Z2016-11-30T15:42:37ZCDS support team

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

cds-question@unistra.fryoung-stellar-objectsstellar-spectral-typesline-intensitiesstellar-massesstellar-distancesurveysWe present our investigation of 319 Class II objects in Orion A observed by Spitzer/IRS. We also present the follow-up observations of 120 of these Class II objects in Orion A from the Infrared Telescope Facility/SpeX. We measure continuum spectral indices, equivalent widths, and integrated fluxes that pertain to disk structure and dust composition from IRS spectra of Class II objects in Orion A. We estimate mass accretion rates using hydrogen recombination lines in the SpeX spectra of our targets. Utilizing these properties, we compare the distributions of the disk and dust properties of Orion A disks with those of Taurus disks with respect to position within Orion A (Orion Nebular Cluster [ONC] and L1641) and with the subgroups by the inferred radial structures, such as transitional disks (TDs) versus radially continuous full disks (FDs). Our main findings are as follows. (1) Inner disks evolve faster than the outer disks. (2) The mass accretion rates of TDs and those of radially continuous FDs are statistically significantly displaced from each other. The median mass accretion rate of radially continuous disks in the ONC and L1641 is not very different from that in Taurus. (3) Less grain processing has occurred in the disks in the ONC compared to those in Taurus, based on analysis of the shape index of the 10{mu}m silicate feature (F_11.3_/F_9.8_). (4) The 20-31{mu}m continuum spectral index tracks the projected distance from the most luminous Trapezium star, {theta}^1^ Ori C. A possible explanation is UV ablation of the outer parts of disks.2016ApJS..226....8Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/226/8CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/319 : UKIDSS-DR9 LAS, GCS and DXS Surveys (Lawrence+ 2012)II/311 : WISE All-Sky Data Release (Cutri+ 2012)II/171 : Parenago Catalog of Stars in Orion Nebula (Parenago 1954)J/ApJS/224/5 : Herschel Orion Protostar Survey (HOPS): SEDs (Furlan+, 2016)J/AJ/146/85 : Spectral types of optical stars in ONC (Hillenbrand+, 2013)J/ApJS/208/9 : Intrinsic colors and temperatures of PMS stars (Pecaut+, 2013)J/ApJS/207/5 : YSOs in LDN 1641 with Hectochelle spectra (Fang+, 2013)J/ApJ/769/149 : IR spectroscopy in Orion A: transitional disks (Kim+, 2013)J/ApJ/767/36 : APEX observations of HOPS protostars (Stutz+, 2013)J/ApJ/764/114 : BVRI photometry of stars in Orion A (Hsu+, 2013)J/AJ/144/192 : Spitzer survey of Orion A & B. I. YSO catalog (Megeath+, 2012)J/ApJ/752/59 : Low-mass population in L1641 (Hsu+, 2012)J/AJ/139/950 : JHKs photometry in ONC (Robberto+, 2010)J/ApJS/183/261 : Optical photometry of the ONC (Da Rio+, 2009)J/MNRAS/400/603 : New variables in ONC (Parihar+, 2009)J/ApJ/703/1964 : Spectra of three nearby star-forming regions (Furlan+, 2009)J/A+A/504/461 : YSOs in L1630N and L1641 (Fang+, 2009)J/ApJ/697/1103 : Kinematics of Orion Nebula Cluster (Tobin+, 2009)J/ApJS/181/321 : Properties of Spitzer c2d dark clouds (Evans+, 2009)J/ApJ/693/L81 : Extinction in star-forming regions (McClure, 2009)J/A+A/489/1409 : IR photometry and spectroscopy in L1641N (Galfalk+, 2008)J/ApJ/677/401 : Xray properties of protostars in ONC (Prisinzano+, 2008)J/ApJ/676/1109 : Velocities of stars in Orion Nebula Cluster (Furesz+, 2008)J/ApJ/671/1784 : Ori OB1 IRAC/MIPS observations (Hernandez+, 2007)J/A+A/461/183 : Variability of classical T Tauri (Grankin+, 2007)J/ApJ/601/979 : vsini of Orion low-mass stars (Wolff+, 2004)J/AJ/121/1676 : ONC low-mass stars photometry (Rebull+, 2001)J/ApJ/540/236 : KH photometry of Orion Nebula Cluster (Hillenbrand+, 2000)J/AJ/119/3026 : Circumstellar disk candidates in Orion (Rebull+, 2000)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/ApJS/226/8https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJS/226/8http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJS/226/8https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJS/226/8https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJS/226/8http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJS/226/8GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJS/226/8/classII (IRS spectra log of observations and identifications of the 319 Class II disks)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/226/8/classII?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/226/8/classII?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/226/8/classII?GETtext/xml+votable180.050000true83.3688333-5.29060.0055555555555555566/21403 21425 21427 21428 21430 21433 21435 21436 21438 21439 22804 22805https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJS/226/8?format=asciiOpticaldefaultJ/ApJS/226/8/table8Grain propertiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqRunning sequence number (G1)meta.id;meta.mainintModModule used (SL or SLLL)instr.setupcharEW10[-13/528]? Equivalent width of 10um featureumspect.line.eqWidth;em.IR.8-15umfloatnullablee_EW10[0.05/54]? Uncertainty in EW10umstat.errorfloatnullableEW20[-1/20]? Equivalent width of 20um featureumspect.line.eqWidth;em.IR.15-30umfloatnullablee_EW20[0.2/1]? Uncertainty in EW20umstat.errorfloatnullableF10[-6/249]? Integrated 10um feature flux (2)1e-15W.m**-2phot.fluxfloatnullablee_F10[0.003/16]? Uncertainty in F101e-15W.m**-2stat.errorfloatnullableF20[-0.1/58]? Integrated 20um feature flux (2)1e-15W.m**-2phot.fluxfloatnullablee_F20[0.01/29]? Uncertainty in F201e-15W.m**-2stat.errorfloatnullableF11.3/F9.8[-26/26]? Ratio of 11.3 to 9.8um flux (3)phot.flux;arith.ratiofloatnullablee_F11.3/F9.8[0/190]? Uncertainty in F11.3/F9.8stat.errorfloatnullableTDFD? Disk type: FD=full disk (189 sources) or TD=Transitional disk (65 sources)src.classcharJ/ApJS/226/8/table3Observation log of SpeX spectrarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/303] Running sequence number (G1)meta.id;meta.mainintm_SeqComponent identifier (1)meta.code.multipcharDateUT date of the observationtime.epoch;obsnullableWidth[0.3/0.8] Slit widtharcsecspect.line.widthfloatTint[80/2520] Total integration timestime.epochintPA[-55/90]? Position angle of slitdegpos.posAngfloatnullableNoteBinary system note (2)meta.notecharJ/ApJS/226/8/table4Spectral type and extinctionrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqRunning sequence number (G1)meta.id;meta.mainintIRSIRS identifier (DDddddd+Dddd; J2000 or HOPS-NNN)meta.idcharSpTlLiterature spectral types (see refs.dat file for references in parenthesis)src.spTypecharSpTAdopted MK spectral typesrc.spTypecharEWHa[-263/49]? Equivalent width of H{alpha}; in Angstroms (3)0.1nmspect.line.eqWidth;em.line.HalphafloatnullableEWLi[0/2]? Equivalent width of Li line; in Angstroms (3)0.1nmspect.line.eqWidthfloatnullableAv[0/35]? Adopted V band extinctionmagphys.absorption;em.opt.Vfloatnullablee_Av[0/32]? Lower uncertainty in Avmagstat.errorfloatnullableE_Av[0/12]? Upper uncertainty in Avmagstat.error;stat.maxfloatnullablen_AvMethod used to determine the adopted Av (4)meta.notecharJ/ApJS/226/8/table6Basic stellar properties and mass accretion raterecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintType[ab] Observation type (1)meta.notecharSeqRunning sequence number (G1)meta.id;meta.mainintIRSIRS identifier (DDddddd+Dddd; J2000 or HOPS-NNN)meta.idcharTeff[2610/9700]? Effective temperatureKphys.temperature.effectiveintnullableL*[0.01/195]? Stellar luminositysolLumphys.luminosityfloatnullableM*[0.09/4.5]? Stellar masssolMassphys.massfloatnullablee_M*[0.02/0.3]? Error in M*solMassstat.errorfloatnullablel_dM/dtLimit flag on dM/dtmeta.code.errorchardM/dt[0.1/1376]? Accrection rate1e-09solMass.yr**-1arith.ratefloatnullablee_dM/dt[0.04/572]? Error in dM/dt1e-09solMass.yr**-1stat.errorfloatnullableJ/ApJS/226/8/table7Spectral indicesModModule used (SL or SLLL)instr.setupcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqRunning sequence number (G1)meta.id;meta.mainintnK-6[-3/4]? K band (2.17um) to 5.4-6.0um spectral indexspect.indexfloatnullablee_nK-6[0.03/1.3]? Uncertainty in nK-6stat.errorfloatnullablen6-13[-4/1]? 5.4-6.0 to 12.8-14.0um spectral indexspect.indexfloatnullablee_n6-13[0.03/5]? Uncertainty in n6-13stat.errorfloatnullablen13-31[-2.5/3]? 12.8-14.0 to 30.3-31.0um spectral indexspect.indexfloatnullablee_n13-31[0.02/3]? Uncertainty in n13-31stat.errorfloatnullablen5-12[-5.1/1]? 5.2-5.54 to 12.8-14.0um spectral indexspect.indexfloatnullablee_n5-12[0.02/2.1]? Uncertainty in n5-12stat.errorfloatnullablen12-20[-2.2/4]? 12.7-13.1 to 19.7-19.95um spectral indexspect.indexfloatnullablee_n12-20[0.02/5]? Uncertainty in n12-20stat.errorfloatnullablenK-25[-2/1]? K band (2.17um) to 24.5-25.5um spectral indexspect.indexfloatnullablee_nK-25[0.01/0.3]? Uncertainty in nK-25stat.errorfloatnullableJ/ApJS/226/8/classIIIRS spectra log of observations and identifications of the 319 Class II disksSimbadNameSimbad column added by the CDSmeta.idcharSeqRunning sequence number (G1)meta.id;meta.mainintprimaryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNsDisplay the SpeX observation log for this source if anymeta.ref.urlintnullableMmore data for this objectmeta.ref.urlcharIRSIRS identifier (2)meta.idcharRAJ2000[5] Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000[4/8] Degree of Declination (J2000)pos.eq.dec;meta.mainAORIDSpitzer AORID observation identifiermeta.id;obs.param;obsintCampIRS Campaign number (36, 39, 40, 44 or 56)meta.id;obsintDateDate of the observationtime.epochnullableModModule used in the observation (SL or SLLL)instr.setupcharRegObservation region (L1641, ONC or Trapezium)obs.fieldcharRedReduction used (3)meta.notecharf_RedFlag on Red (4)meta.codecharn_AORIDExtra note on the IRS program ID (5)meta.notechar2MASS2MASS identifier (HHMMSSss+DDMMSSs; J2000)meta.idcharONameOther name(s) selected (3)meta.idcharf_ONameFlag on OName (4)meta.codecharK13Display data from transitional disk catalog of Kim+, 2013, J/ApJ/769/149, within 1"meta.ref.urlintnullableM12Display Spitzer data from Megeath+, 2012, J/AJ/144/192, within 2"meta.ref.urlintnullableOCatDisplay data from Parenago, 1954, II/171; Furesz+, 2008, J/ApJ/676/1109; Herbig+, 1988, V/73; Furlan+, 2016, J/ApJS/224/5 and the GCVS (B/gcvs), within 3"meta.ref.urlintnullableJ/ApJS/226/8/table11n_20-31_ and the projected distance from {theta}^1^ Ori CrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqRunning sequence number (G1)meta.id;meta.mainintn20-31[-4/3]? 19.7-19.95 to 30.3-31.0um spectral indexspect.indexfloatnullablee_n20-31[0.02/6]? Uncertainty in n20-31stat.errorfloatnullabled[102/12986] Projected angular distance (2)arcsecpos.angDistancefloatDist[0.2/27] Projected linear distance (2)pcpos.distancefloatSecSection (3)meta.bib.figcharJ/ApJS/226/8/refsReferences (for table 4)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRefReference code (as in table 4)meta.notecharBibCodeADS/SIMBAD bibcode if anymeta.bib.bibcodecharAutFirst author's name(s)meta.bib.authorcharCommCommentmeta.notechar