J/ApJ/919/116 High-resolution NIR spectra of IRAS 16316-1540 (Yoon+, 2021)
Evidence of accretion burst: the viscously heated inner disk of the embedded
protostar IRAS 16316-1540.
Yoon S.-Y., Lee J.-E., Lee S., Herczeg G.J., Park S., Mace G.N.,
Lee J.-J., Jaffe D.T.
<Astrophys. J., 919, 116 (2021)>
=2021ApJ...919..116Y 2021ApJ...919..116Y
ADC_Keywords: YSOs; Spectra, infrared
Keywords: Protostars ; Protoplanetary disks ; Young stellar objects ;
High resolution spectroscopy
Abstract:
Outbursts 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.
Description:
We obtained the NIR spectra of IRAS 16316-1540 using Immersion Grating
Infrared Spectrograph (IGRINS). IGRINS is a cross-dispersed
spectrograph that obtains simultaneous H- and K-band spectra with a
resolution R∼45000. We observed IRAS 16316-1540 at the 2.7m Harlan J.
Smith telescope (HJST) of the McDonald Observatory from 2015 April 30
to 2017 August 3, the 4.3m Discovery Channel Telescope (DCT) of the
Lowell Observatory on 2017 September 3, and the Gemini-South Telescope
(GST) of the Gemini Observatory on 2018 June 2.
Objects:
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RA (ICRS) DE Designation(s)
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16 34 29.31 -15 47 01.3 IRAS 16316-1540 = HBC 650
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
obs.dat 68 48 Summary of the IGRINS spectra files
in subdirectory "fits"
fits/* . 48 Individual IGRINS spectra of IRAS 16316-1540 in
the H and K bands in FITS format
(Data behind Figure 1)
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See also:
J/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 Pfβ (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)
Byte-by-byte Description of file: obs.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Tel Telescope (1)
6- 14 A9 --- Type Data type (2)
16 A1 --- Filt [KH] Passband
18- 27 A10 "Y/M/D" Date Observation date (UT)
29- 68 A40 --- FileName Name of the FITS file in subdirectory "fits"
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Note (1): Telescope (see Table 1) as follows:
HJST = the 2.7m Harlan J. Smith telescope of the McDonald Observatory
DCT = the 4.3m Discovery Channel Telescope of the Lowell Observatory
GST = the Gemini-South Telescope of the Gemini Observatory
Note (2): For every observation date in a band, there are three data files:
wave, flux and obs_error. The error is the fractional error.
Therefore, the absolute error can be derived by multiplying data in
two files of flux and obs_error.
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 31-Jan-2023