J/ApJ/919/116ivo://CDS.VizieR/J/ApJ/919/116doi:10.26093/cds/vizier.19190116CDSYoon S.-Y.Lee J.-E.Lee S.Herczeg G.J.Park S.Mace G.N.,Lee J.-J.Jaffe D.T.2023-05-26T09:03:25Z2023-03-03T10:07:44ZCDS support team

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

cds-question@unistra.fryoung-stellar-objectsinfrared-astronomyspectroscopyOutbursts of young stellar objects occur when the mass accretion rate suddenly increases. However, such outbursts are difficult to detect for deeply embedded protostars due to their thick envelope and the rarity of outbursts. The near-IR spectroscopy is a useful tool to identify ongoing outburst candidates by the characteristic absorption features that indicate a disk origin. However, without high-resolution spectroscopy, the spectra of outburst candidates can be confused with the late-type stars since they have similar spectral features. For the protostar IRAS 16316-1540, the near-IR spectrum has line equivalent widths that are consistent with M-dwarf photospheres. However, our high-resolution IGRINS spectra reveal that the absorption lines have boxy and/or double-peaked profiles, as expected from a disk and not the star. The continuum emission source is likely the hot, optically thick disk, heated by viscous accretion. The projected disk rotation velocity of 41+/-5km/s corresponds to ~0.1au. Based on the result, we suggest IRAS 16316-1540 as an ongoing outburst candidate. Viscous heating of disks is usually interpreted as evidence for ongoing bursts, which may be more common than previously estimated from low-resolution near-IR spectra.2021ApJ...919..116Yhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/919/116CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/ApJS/94/615 : Molecular outflow sources (Hodapp, 1994)J/ApJS/101/117 : UBVRIJHKLMNQ photometry in Taurus-Auriga (Kenyon+ 1995)J/ApJS/111/445 : Spectra of normal stars in the K band (Wallace+ 1997)J/AJ/130/1145 : YSO near-infrared properties (Doppmann+, 2005)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/ApJ/769/21 : Accretion lum. of young stars from Pf{beta} (Salyk+, 2013)J/ApJ/794/125 : IN-SYNC. I. APOGEE stellar parameters (Cottaar+, 2014)J/ApJ/786/97 : Photospheric properties of T Tauri stars (Herczeg+, 2014)J/MNRAS/465/3039 : Eruptive variable protostars from VVV EW (Contreras+, 2017)J/ApJS/238/29 : IGRINS spectral library (Park+, 2018)J/MNRAS/486/4590 : 139 high-amplitude variable stars (Contreras+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/919/116https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/919/116http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/919/116https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/919/116https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/919/116http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/919/116GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapInfrareddefaultJ/ApJ/919/116/obsSummary of the IGRINS spectra files in subdirectory "fits"recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTelTelescope (1)meta.id;instr.telcharTypeData type (2)meta.codecharFilt[KH] Passbandinstr.bandpasscharDateObservation date (UT)time.epoch;obsnullableFileNameName of the FITS file in subdirectory "fits"meta.id;meta.fitscharSpInteractive spectrum plotmeta.ref.urlchar