J/AJ/164/227 NIR spectra of 2M1155-79A and B (Dickson-Vandervelde+, 2022)
Investigating 2M1155-79B; A Nearby, Young, Low-mass Star Actively Accreting from
a Nearly Edge-on, Dusty Disk.
Dickson-Vandervelde D.A., Kastner J.H., Gagne J., Schneider A.C.,
Faherty J., Wilson E.C., Pinte C., Menard F.
<Astron. J., 164, 227 (2022)>
=2022AJ....164..227D 2022AJ....164..227D
ADC_Keywords: Exoplanets; Stars, pre-main sequence; Spectra, infrared
Keywords: Protoplanetary disks ; Pre-main sequence stars
Abstract:
We investigate the nature of an unusually faint member of the
εCha association (D∼100pc, age ∼5Myr), the nearest region of
star formation of age <8Myr. This object, 2MASSJ11550336-7919147
(2M1155-79B), is a wide-separation (∼580au), comoving companion to
low-mass (M3) εCha association member 2MASSJ11550485-7919108
(2M1155-79A). We present near-infrared (NIR) spectra of both
components, along with analysis of photometry from Gaia Early Data
Release 3, the Two Micron All Sky Survey, the Vista Hemisphere Survey,
and the Wide-field Infrared Survey Explorer (WISE). The NIR spectrum
of 2M1155-79B displays strong HeI 1.083 emission, a sign of active
accretion and/or accretion-driven winds from a circumstellar disk.
Analysis of WISE archival data reveals that the mid-infrared excess
previously associated with 2M1155-79A instead originates from the disk
surrounding 2M1155-79B. Based on these results, as well as radiative
transfer modeling of its optical/IR spectral energy distribution, we
conclude that 2M1155-79B is most likely a young, late M star that is
partially obscured by, and actively accreting from, a nearly edge-on
circumstellar disk. This would place 2M1155-79B among the rare group
of nearby (D≲100pc), young (age <10Myr) mid-M stars that are orbited
by and accreting from highly inclined protoplanetary disks. Like these
systems, the 2M1155-79B system is a particularly promising subject for
studies of star and planet formation around low-mass stars.
Description:
NIR spectra were obtained on 2020 February 12 and 13 (hereafter Night
1 and Night 2, respectively) using the Folded port InfraRed Echellette
(FIRE) instrument on the 6.5m Magellan telescope. FIRE spectra were
obtained in prism mode, which has a resolving power of ∼450 across the
0.8-2.5µm spectral range.
Objects:
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RA (2000) DE Designation(s)
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11 55 03.29 -79 19 14.9 2MASS J11550336-7919147 = 2MASS J11550336-7919147
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
fig1.dat 38 6134 Near-IR spectra obtained with the FIRE instrument
on Magellan for 2M1155-79A and 2M1155-79B
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See also:
II/359 : The VISTA Hemisphere Survey (VHS) catalog DR4.1 (McMahon+, 2013)
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
II/363 : The band-merged unWISE Catalog (Schlafly+, 2019)
I/352 : Distances to 1.47 billion stars in Gaia EDR3 (Bailer-Jones+, 2021)
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
J/MNRAS/435/1325 : Membership of the ε Cha association (Murphy+, 2013)
J/ApJS/208/9 : Intrinsic colors and temperatures of PMS stars (Pecaut+, 2013)
J/AJ/153/46 : Spectroscopy of candidate members in Taurus (Luhman+, 2017)
J/ApJ/862/138 : BANYAN. XIII. Nearby young assoc. with Gaia DR2 (Gagne+, 2018)
J/A+A/625/A135 : Galactic interstellar dust Gaia2MASS 3Dmaps (Lallement+, 2019)
J/AJ/160/44 : Upper Scorpius spectroscopy and photometry (Luhman+, 2020)
J/MNRAS/502/6117 : A faint companion around CrA-9 (Christiaens+, 2021)
J/AJ/161/87 : Gaia data members of εCha (Dickson-Vandervelde+, 2021)
J/MNRAS/503/2265 : VISTA and Subaru/HSC obs. of Upper Scorpius (Lodieu+, 2021)
Byte-by-byte Description of file: fig1.dat
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Bytes Format Units Label Explanations
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1- 1 I1 --- Date Observation date code (1)
3- 12 A10 --- ID Object identifier
14- 19 F6.4 um Wave [0/3] Wavelength
21- 29 E9.2 cW/m2/nm Flux [-4e-14/2] Flux density; erg/s/cm2/A
31- 38 E8.2 cW/m2/nm e_Flux [0/19]Uncertainty in Flux; erg/s/cm2/A
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Note (1): Code as follows:
1 = Feb 12, 2020;
2 = Feb 13, 2020.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 09-Dec-2022