J/ApJ/921/110ivo://CDS.VizieR/J/ApJ/921/110doi:10.26093/cds/vizier.19210110CDSLaos S.Greene T.P.Najita J.R.Stassun K.G.2023-06-15T09:20:36Z2023-03-29T08:44:24ZCDS support team

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

cds-question@unistra.fryoung-stellar-objectsinfrared-astronomyspectroscopystar-forming-regionsmolecular-cloudsWe present near-infrared K-band spectra for a sample of seven Class 0 protostars in the Perseus and Orion star-forming regions. We detect Br{gamma}, CO overtone, and H_2_ emission, features that probe the near-circumstellar environment of the protostar and reveal evidence of magnetospheric accretion, a hot inner disk atmosphere, and outflows, respectively. Comparing the properties of these features with those of Class I sources from the literature, we find that their Br{gamma} emission and CO emission are generally consistent in strength and velocity width. The Br{gamma} line profiles are broad and centrally peaked, with FWHMs of ~200km/s and wings extending to ~300km/s. The line ratios of our H_2_ emission features, which are spatially extended for some sources, are consistent with shock excitation and indicate the presence of strong jets or a disk wind. Within our small sample, the frequency of CO band emission (~67%) is high relative to that of Class I samples (~15%), indicating that Class 0 sources have high inner disk accretion rates, similar to those of the most actively accreting Class I sources. Collectively, our results suggest that Class 0 sources have similar accretion mechanisms to the more evolved classes, with strong organized stellar magnetic fields established at the earliest observable stage of evolution.2021ApJ...921..110Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/921/110CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)II/319 : UKIDSS-DR9 LAS, GCS and DXS Surveys (Lawrence+ 2012)J/A+A/356/1010 : Ortho:para-H2 ratio in C and J shocks (Wilgenbus+, 2000)J/A+A/365/90 : NIR H lines in TTS (Folha+, 2001)J/AJ/130/1145 : YSO near-infrared properties (Doppmann+, 2005)J/ApJ/638/293 : 1.1mm sources in the Perseus Molecular Cloud (Enoch+, 2006)J/ApJ/646/1009 : Structures of dust in Perseus molecular cloud (Kirk+, 2006)J/MNRAS/387/954 : H2 imaging of NGC 1333, L1455, L1448 and B1 (Davis+, 2008)J/ApJS/181/321 : Properties of Spitzer c2d dark clouds (Evans+, 2009)J/AJ/140/1214 : NIR spectroscopic survey of class I YSOs (Connelley+, 2010)J/AJ/144/31 : Spitzer+2MASS phot. of protostar cand. (Kryukova+, 2012)J/AJ/144/192 : Spitzer survey of Orion A & B. I. YSOs (Megeath+, 2012)J/ApJ/767/36 : APEX observations of HOPS protostars (Stutz+, 2013)J/ApJS/220/11 : SEDs of Spitzer YSOs in the Gould Belt (Dunham+, 2015)J/AJ/150/17 : A catalog of point sources toward NGC 1333 (Rebull, 2015)J/ApJS/224/5 : The Herschel Orion Protostar Survey: SEDs (Furlan+, 2016)J/ApJS/224/40 : Catalog of Chandra ACIS point like sources (Wang+, 2016)J/MNRAS/465/3039 : Eruptive variable protostars from VVV EW (Contreras+, 2017)J/ApJS/229/28 : SFiNCs: X-ray, IR and membership catalogs (Getman+, 2017)J/ApJ/834/142 : Gould's Belt Distances Survey. II. OMC (Kounkel+, 2017)J/ApJ/865/73 : GOBELINS. V. Kinematics of Perseus (Ortiz-Leon+, 2018)J/ApJS/238/19 : VANDAM IV. Free-free emission (Tychoniec+, 2018)J/ApJ/890/130 : VANDAM survey of Orion protostars. II. (Tobin+, 2020)J/A+A/633/A51 : Distances to molecular clouds in SFR (Zucker+, 2020)J/A+A/650/A43 : Sp. of NGC 1333 Class I-Class II stars (Fiorellino+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/921/110https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/921/110http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/921/110https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/921/110https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/921/110http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/921/110GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/921/110/table1 (*Journal of observations)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/921/110/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/921/110/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/921/110/table1?GETtext/xml+votable180.050000true51.41166730.7350560.0055555555555555566/858-859 862 1539 21438https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/921/110?format=asciiInfrareddefaultJ/ApJ/921/110/table1*Journal of observationsSimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameObject namemeta.id;meta.maincharRegRegionmeta.id.parentcharRAJ2000NIR hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ2000NIR degree of declination (J2000)pos.eq.dec;meta.mainDateDate of observation (UT)time.epochnullableExp[12/34] Integration timemintime.expointExt[0.7/3.4]? Spatial extent (1)arcsecphys.angSizefloatnullableVsys[5.4/11]? Systemic velocity (2)km/sphys.velocfloatnullableFileName of the ASCII file in subdirectory "sp"; column added by CDSmeta.id;meta.filecharSpInteractive spectrum plotmeta.ref.urlchar