J/AJ/165/205 LAMOST study, masses & ages of 823 TTauri stars (Hernandez+, 2023)
A LAMOST Spectroscopic Study of T Tauri Stars in the Orion OB1a Subassociation.
Hernandez J., Zamudio L.F., Briceno C., Calvet N., Zhu Z., Yuan H.,
Liu X., Manzo-Martinez E., Roman-Zuniga C.G., Serna J., Mauco K.,
Adame L.
<Astron. J., 165, 205 (2023)>
=2023AJ....165..205H 2023AJ....165..205H
ADC_Keywords: Stars, variable; Star Forming Region; Spectra, optical;
Extinction; Stars, ages; Stars, masses
Keywords: Star forming regions ; OB associations ; Hertzsprung Russell
diagram ; Pre-main sequence ; T Tauri stars ; Stellar spectral
types ; Stellar kinematics ; Protoplanetary disks
Abstract:
We present a spectroscopic analysis of TTauri stars (TTSs) observed
with the wide-field multifiber spectrograph LAMOST in the substellar
associations Ori OB1a located in the Orion Star-forming Complex. Based
on GAIA-DR3 data, we selected stars with proper motions and parallaxes
expected for TTSs belonging to the young association. We perform a
spectroscopic analysis to obtain the spectral types and measure the
equivalent widths of LiI and Hα to confirm the youth of the
stars and estimate the accretion status. We also estimate extinctions,
masses, and ages for the studied sample. Out of 342 TTSs with
spectroscopic and kinematic properties indicating their membership of
the subassociation, 2 are reported here for the first time. Finally,
we detect four stellar kinematic groups located at different
distances, two in the north fields and two in the south field. These
groups also show different proper motions. This suggests that the
star-forming scenario in this region is more complex than the
traditional spatial-temporal scenario, in which a generation of stars
triggers the formation of a new spatially differentiated generation of
stars.
Description:
Large Sky Area Multi-Object Fibre Spectroscopic Telescope (LAMOST) is
a multifiber spectrograph mounted on the 4m Schmidt telescope of the
National Astronomical Observatory of China, located at the Xinglong
Observing Station. LAMOST covers an area of ∼20deg2 (with a diameter
of 5deg) with 4000 fibers provided by 16 spectrographs. Each
spectrograph includes 250 fibers and has a blue arm and a red arm
covering a spectral range of 3700-5900Å and 5700-9000Å,
respectively (R=1800).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 123 823 Spectroscopic and kinematic analysis
table3.dat 144 823 Extinctions, masses and ages
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See also:
II/36 : UBV and uvby-beta observations of Orion OB1 Association (Warren+ 1977)
I/317 : The PPMXL Catalog (Roeser+ 2010)
I/352 : Distances to 1.47 billion stars in Gaia EDR3 (Bailer-Jones+, 2021)
V/137 : Extended Hipparcos Compilation (XHIP) (Anderson+, 2012)
J/A+A/289/101 : Orion OB1 association. I. (Brown+, 1994)
J/AJ/117/354 : OB associations from Hipparcos (de Zeeuw+, 1999)
J/AJ/123/387 : VRI photometry λOri star-forming region (Dolan+, 2002)
J/AJ/128/2316 : BVRIJHKs photometry in sigma Ori cluster (Sherry+, 2004)
J/AJ/129/907 : New Ori OB1 members (Briceno+, 2005)
J/AJ/129/856 : Herbig Ae/Be stars in nearby OBassociations (Hernandez+, 2005)
J/A+A/440/403 : 109 new Galactic open clusters (Kharchenko+, 2005)
J/ApJS/179/451 : Predicted IR excesses for protoplanetary disks (Kenyon+, 2008)
J/ApJ/688/362 : Disks around brown dwarf in σOri cluster (Luhman+, 2008)
J/ApJS/191/389 : Photometric monitoring in σ Ori cluster (Cody+, 2010)
J/ApJ/752/59 : Low-mass population in L1641 (Hsu+, 2012)
J/ApJ/758/31 : IR photometry for members of Upper Sco (Luhman+, 2012)
J/A+A/558/A53 : Milky Way global survey star clusters. II. (Kharchenko+, 2013)
J/ApJS/208/9 : Intrinsic colors and temperatures of PMS stars (Pecaut+, 2013)
J/MNRAS/444/1793 : 25 Ori group low-mass stars (Downes+, 2014)
J/ApJ/784/126 : IR photometry of all known members in Taurus (Esplin+, 2014)
J/ApJ/794/36 : σ Orionis cluster stellar population (Hernandez+, 2014)
J/MNRAS/472/3887 : Kinematic data for stars in OB-associations (Melnik+, 2017)
J/AJ/156/71 : K2 Campaign 2; young disk-bearing * in Sco & Oph (Cody+, 2018)
J/AJ/156/84 : APOGEE-2 survey of Orion Complex. II. (Kounkel+, 2018)
J/A+A/620/A172 : Solar neighbourhood young stars 3D mapping (Zari+, 2018)
J/AJ/157/85 : The CIDA Variability Survey of Orion OB1. II. (Briceno+, 2019)
J/A+A/631/A166 : Members of 5 cluster in Ori OB1a association (Kos+, 2019)
J/AJ/158/122 : Local structure &star formation history of MW (Kounkel+, 2019)
J/ApJ/884/6 : Known members of Orion A with Gaia DR2 data (McBride+, 2019)
J/AJ/158/48 : Speckle interferometry at SOAR in 2018 (Tokovinin+, 2019)
J/A+A/633/A99 : Gaia DR2 open clusters in Milky Way. II (Cantat-Gaudin+, 2020)
J/AJ/160/44 : Upper Scorpius spectroscopy and photometry (Luhman+, 2020)
J/ApJ/893/56 : TTauri star IR excesses & Ha eq widths (Manzo-Martinez+, 2020)
J/MNRAS/495/3104 : Runaway and walkaway stars from the ONC (Schoettler+, 2020)
J/AJ/160/268 : Infrared photometry binaries in Orion OB1 (Tokovinin+, 2020)
J/ApJ/917/23 : SPYGLASS. I. Mapping young stellar structures (Kerr+, 2021)
J/A+A/649/A3 : Gaia Early Data Release3 photometric passbands (Riello+, 2021)
J/ApJ/923/177 : TESS obs. & rotational periods TTauri in Orion (Serna+, 2021)
J/AJ/162/101 : K2 ugri & Hα photometry in Lagoon Nebula (Venuti+, 2021)
J/A+A/657/A7 : Stellar & substellar companions Gaia EDR3 (Kervella+, 2022)
J/A+A/664/A175 : Milky Way low mass young stars Gaia EDR3 (Prisinzano+, 2022)
J/ApJS/258/16 : TESS Eclipsing Binary stars. I. Sectors 1-26 (Prsa+, 2022)
J/AJ/163/152 : Stellar parameters for ∼650000 stars APOGEE (Sprague+, 2022)
J/AJ/163/74 : Census of low accretors. I. The catalog (Thanathibodee+, 2022)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- 2MASS 2MASS Position-based identifier
19- 22 A4 --- CVSO CIDA Variability Survey of Orion identifier
24- 42 I19 --- Gaia Gaia EDR3 identifier
44- 51 F8.5 deg RAdeg [78/88] Right Ascension (J2000)
53- 60 F8.5 deg DEdeg [-5/7] Declination (J2000)
62- 66 F5.2 --- RUWE [0.91/31.5]? Gaia EDR3 RUWE metric
68- 71 F4.2 --- fid [0.01/1]? Fidelity (1)
73- 77 A5 --- fkin Kinematic flag (2)
79- 82 A4 --- SpT Spectral Type
84- 86 F3.1 --- e_SpT [0.5/4.5] Uncertainty in SpT
88- 88 I1 --- fLi [0/2] Flag on Li detection (3)
90- 92 F3.1 0.1nm EWLi [0/2.1] Equivalent Width, Li
94- 98 F5.1 0.1nm EWHa [-70.6/13.6]? Equivalent Width, Hα
100-101 A2 --- facc Accretion-class flag (4)
103-109 A7 --- fbf bona fide TTS flag (5)
111-123 A13 --- Ref Reference(s) (6)
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Note (1): Rybizki+, 2022MNRAS.510.2597R 2022MNRAS.510.2597R fidelity_v2 parameter for the
quality of the astrometric measurement in Gaia EDR3
Note (2): Flags as follows:
K_MEM = stars with good astrometric quality that fall within the
membership region defined in Figure 3 (555 occurrences)
K_NM = stars with good astrometric quality that fall outside the
membership limits defined in Figure 3 (31 occurrences)
K_UNC = Stars with uncertain kinematic status, including sources
that do not meet the good astrometric quality criteria (not
included in Figure 3) (153 occurrences)
Note (3): Flags as follows:
2 = reliable (503 occurrences)
1 = doubtful (193 occurrences)
0 = non-detection (127 occurrences)
Note (4): Flag as follows:
C = Classical TTS (16 occurrences)
W = Weak-lined TTS (624 occurrences)
CW= stars between CTTS and WTTS (36 occurrences)
Note (5): Flags as follows:
1 = bona fide TTS using the RUWE (342 occurrences)
2 = bona fide TTS using the fidelity kinematic quality criteria
(75 occurrences)
r.tts = runaway TTS (3 occurrences)
w.tts = walkaway TTS (2 occurrences)
Note (6): References as follows:
1 = Briceno+, 2019, J/AJ/157/85B
2 = Sprague+, 2022, J/AJ/163/152
3 = Zari+, 2018, J/A+A/620/A172
4 = Kounkel+, 2019, J/AJ/158/122
5 = Cantat+, 2020, J/A+A/633/A99
6 = Kos+, 2019, J/A+A/631/A166
7 = Prisinzano+, 2022, J/A+A/664/A175
8 = Kerr+, 2021, J/ApJ/917/23
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- 2MASS 2MASS Position-based identifier
19- 19 I1 --- fph [0/1] Gaia EDR3 ph_flag (1)
21- 25 F5.2 mag AJmag [0/1.43] J-band extinction
27- 30 F4.2 mag e_AJmag [0/0.3] Uncertainty in AJmag
32- 37 F6.1 K Teff [2912/6531] Stellar surface effective temperature
39- 43 F5.1 K e_Teff [27/632] Uncertainty in Teff
45- 49 F5.2 [Sun] Lum [-2.03/2.66] log, Luminosity
51- 54 F4.2 [Sun] e_Lum [0.02/0.4] Uncertainty in logL
56- 59 F4.2 Msun Mass*1 [0.14/5.43]? Stellar mass, parsec
61- 64 F4.2 Msun E_Mass*1 [0/0.9]? Lower uncertainty in Mass*1
66- 69 F4.2 Msun e_Mass*1 [0/2]? Upper uncertainty in Mass*1
71- 76 F6.2 Myr Age1 [0.1/233]? Age, parsec
78- 82 F5.2 Myr E_Age1 [0.02/79]? Lower uncertainty in Age1
84- 88 F5.2 Myr e_Age1 [0/72]? Upper uncertainty in Age1
90- 91 I2 --- fhd1 [-1/1] hd flag PARSEC (2)
93- 96 F4.2 Msun Mass*2 [0.12/5.35]? Stellar mass, MIST
98-101 F4.2 Msun E_Mass*2 [0.01/10]? Lower uncertainty in Mass*2
103-106 F4.2 Msun e_Mass*2 [0.01/2]? Upper uncertainty in Mass*2
108-113 F6.2 Myr Age2 [0.01/223]? Age, MIST
115-120 F6.2 Myr E_Age2 [0.01/137]? Lower uncertainty in Age2
122-127 F6.2 Myr e_Age2 [0/112]? Upper uncertainty in Age2
129-130 I2 --- fhd2 [-1/1] hd flag MIST (2)
132-144 A13 --- fcl Kinematic/Cluster group flag (3)
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Note (1): ph_flag=0 indicates that the star does not fulfill the
photometric quality criteria described in Section 3.2
Note (2): hd_flag=1 indicates that the star falls near the grid
limits of the evolutionary model on the HR diagram. hd_flag=-1
indicates no fit was possible.
Note (3): BG indicates stars not assigned to a stellar kinematic
group; Stars with "(2)" were assigned to a kinematic group using the
membership cubes described in Section 3.3
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 29-Sep-2023