J/ApJ/782/8ivo://CDS.VizieR/J/ApJ/782/8doi:10.26093/cds/vizier.17820008CDSIngraham P.Albert L.Doyon R.Artigau E.2017-10-12T13:00:26Z2016-03-18T07:44:40ZCDS support team

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

cds-question@unistra.fropen-star-clustersdwarf-starsstellar-spectral-typeseffective-temperatureextinctionstellar-massesWe performed low-resolution (R~40) near-infrared (0.9-2.4{mu}m) multi-object spectroscopy of 240 isolated point sources having apparent H-band magnitudes between 9 and 18 in the central 5'x6' of the Orion Trapezium cluster. The observations were performed over four nights at the Canada-France-Hawaii Telescope using the visiting instrument SIMON, an infrared imager and multi-object spectrograph. We present the spectra of 104 objects with accurately derived spectral types including 7 new objects having masses below the hydrogen-burning limit, and 6 objects with masses below the deuterium-burning limit. The spectral classification is performed by fitting previously classified spectral templates of dwarf stars (K4-M3) and optically classified young stellar and substellar objects (M4-L0), to the entire 0.9-2.4{mu}m spectral energy distribution in order to assign a spectral type and visual extinction for each object. Of the 104 objects studied, 44 have been previously classified spectroscopically using various techniques. We perform a rigorous comparison between the previous classifications and our own and find them to be in good agreement. Using the dereddened H-band magnitudes, the classified objects are used to create an Hertzsprung-Russell diagram for the cluster. We find that the previous age estimates of ~1Myr to be consistent with our results. Consistent with previous studies, numerous objects are observed to have luminosities several magnitudes above the 1Myr isochrone. Numerous objects exhibiting emission features in the J band are also reported.2014ApJ...782....8Ihttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/782/8CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJS/207/10 : HST Treasury Program on the ONC (Robberto+, 2013)J/ApJ/748/14 : ONC population data from WFI observations (Da Rio+, 2012)J/A+A/534/A10 : HST/NICMOS III imaging in ONC (Andersen+, 2011)J/ApJ/722/1092 : Optical photometry of the ONC. II. (Da Rio+, 2010)J/ApJS/183/261 : Optical photometry of the ONC (Da Rio+, 2009)J/AJ/134/2272 : Visual binaries in the Orion Nebula Cluster (Reipurth+, 2007)J/A+A/458/461 : Binary stars in the Orion Nebula Cluster (Koehler+, 2006)J/MNRAS/361/211 : JHK photometry of brown dwarfs in Orion (Lucas+, 2005)J/ApJ/540/236 : KH photometry of Orion Nebula Cluster (Hillenbrand+, 2000)J/AJ/117/1375 : Orion Trapezium cluster (Simon+, 1999)J/AJ/113/1733 : Orion Nebula Cluster population (Hillenbrand 1997)J/AJ/111/846 : Orion HST survey (O'Dell+ 1996)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/782/8https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/782/8http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/782/8https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/782/8https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/782/8http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/782/8GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/782/8/table4 (Previously classified objects)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/782/8/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/782/8/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/782/8/table4?GETtext/xml+votable180.050000true83.7550833-5.36236110.005555555555555556Cone search capability for table J/ApJ/782/8/table5 (Properties of observed sources)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/782/8/table5?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/782/8/table5?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/782/8/table5?GETtext/xml+votable180.050000true83.7545-5.38452780.0055555555555555566/21439https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/782/8?format=asciiOpticaldefaultJ/ApJ/782/8/table4Previously classified objectsSimbadNameSimbad column added by the CDSmeta.idcharRefReference (2)meta.ref;pos.frameintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Hour of Right Ascension (J2000) (G1)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000) (G1)pos.eq.dec;meta.mainNameIdentifier from this work (G2)meta.id;meta.maincharONameOther name (reference identifier)meta.idcharSpTrReference spectral typesrc.spTypechare_SpTr? Uncertainty in SpTrstat.errorfloatnullableSpTSpectral type from this worksrc.spTypecharSpT1Later range in SpTsrc.spTypecharSpT0Early range in SpTsrc.spTypecharAVr[0/10.5]? Reference V band extinctionmagphys.absorptionfloatnullablef_AVrReddening/dereddening flag on AVr (c or d) (3)meta.codecharAV[0/7.5] V band extinction from this workmagphys.absorptionfloate_AV[0/5.9] Lower limit on AVmagstat.errorfloatE_AV[0/8.4] Upper limit on AVmagstat.error;stat.maxfloatSummaryComparison summarymeta.noteJ/ApJ/782/8/table5Properties of observed sourcesSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Hour of Right Ascension (J2000) (G1)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000) (G1)pos.eq.dec;meta.mainNameIdentifier (G2)meta.id;meta.maincharprimaryPSimbad column added by the CDSmeta.ref.urlcharField[1/7] Field number (1, 6, or 7)meta.id;obs.fieldintHmag[9.1/17.8] H band magnitudemagphot.mag;em.IR.Hfloatr_HmagReference or uncertainty flag on Hmag (1)meta.ref;pos.framecharH0mag[8.4/17.8] Dereddened H band magnitudemagphot.mag;em.IR.HfloatSpTSpectral typesrc.spTypecharSpT1Later range in SpTsrc.spTypecharSpT0Early range in SpTsrc.spTypecharAV[0/10.2] The V band extinctionmagphys.absorptionfloate_AV[0/10.7] Lower limit on AVmagstat.errorfloatE_AV[0/10.5] Upper limit on AVmagstat.error;stat.maxfloatTeff[2000/4340] Effective temperatureKphys.temperature.effectiveinte_Teff[2000/3680] Lower limit on TeffKstat.error;phys.temperature.effectiveintE_Teff[2350/5240] Upper limit on TeffKstat.error;stat.maxintl_Mass[>] Lower limit flag on Massmeta.code.error;phys.masscharMass[0.006/1.4]? MasssolMassphys.massfloatnullablee_Mass[0.006/0.814]? Lower limit on MasssolMassstat.error;phys.massfloatnullablen_Mass[>] Indicates E_Mass is a lower limitmeta.notecharE_Mass[0.012/1.4]? Upper limit on MasssolMassstat.error;stat.maxfloatnullableNoteAdditional notesmeta.note