J/ApJ/924/84 λ Orionis PMS stars with Gaia & SPOTS (Cao+, 2022)
Age spreads and systematics in λ Orionis with Gaia DR2 and the SPOTS
tracks.
Cao L., Pinsonneault M.H., Hillenbrand L.A., Kuhn M.A.
<Astrophys. J., 924, 84 (2022)>
=2022ApJ...924...84C 2022ApJ...924...84C
ADC_Keywords: Stars, pre-main sequence; Clusters, open; Star Forming Region;
Stars, masses; Stars, ages; Extinction; YSOs
Keywords: Stellar activity ; Pre-main sequence stars ;
Fundamental parameters of stars ; Star clusters ;
Young star clusters ; Young stellar objects ;
Stellar evolutionary models
Abstract:
In this paper we investigate the robustness of age measurements, age
spreads, and stellar models in young pre-main-sequence stars. For this
effort, we study a young cluster, λ Orionis, within the Orion
star-forming complex. We use Gaia data to derive a sample of
357 targets with spectroscopic temperatures from spectral types or
from the automated spectroscopic pipeline in APOGEE Net. After
accounting for systematic offsets between the spectral type and APOGEE
temperature systems, the derived properties of stars on both systems
are consistent. The complex interstellar medium, with variable local
extinction, motivates a star-by-star dereddening approach. We use a
spectral energy distribution fitting method calibrated on open
clusters for the Class III stars. For the Class II population, we use
a Gaia G-RP dereddening method, minimizing systematics from disks,
accretion, and other physics associated with youth. The cluster age is
systematically different in models incorporating the structural impact
of starspots or magnetic fields than in nonmagnetic models. Our mean
ages range from 2-3Myr (nonmagnetic models) to 3.9±0.2Myr in the
SPOTS model (f=0.34). We find that star-by-star dereddening methods
distinguishing between pre-main-sequence classes provide a smaller age
spread than techniques using a uniform extinction, and we infer a
minimum age spread of 0.19dex and a typical age spread of 0.35dex
after modeling age distributions convolved with observed errors. This
suggests that the λ Ori cluster may have a long star formation
timescale and that spotted stellar models significantly change age
estimates for young clusters.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 127 357 *Inferred stellar parameters with SPOTS fspot=0.34
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Note on table1.dat: the Stellar Parameters of Tracks with Starspots (SPOTS)
models are presented in Somers et al. 2020ApJ...891...29S 2020ApJ...891...29S
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See also:
B/mk : Catalogue of Stellar Spectral Classifications (Skiff, 2009- )
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/ApJS/93/211 : IUE survey of H I Lyα absorption. I. (Diplas+ 1994)
J/ApJS/101/117 : UBVRIJHKLMNQ photometry in Taurus-Auriga (Kenyon+ 1995)
J/AJ/113/1733 : Orion Nebula Cluster population (Hillenbrand 1997)
J/AJ/121/2124 : λ Ori pre-main-sequence stars phot. (Dolan+, 2001)
J/AJ/123/387 : VRI phot. of λ Ori star-forming region (Dolan+, 2002)
J/ApJ/664/481 : Opt/IR photometry of Collinder 69 (Barrado y Navascues+ 2007)
J/A+A/492/277 : Analysis of Collinder 69 stars with VOSA (Bayo+, 2008)
J/A+A/488/167 : Low-mass stars in σ Ori and λ Ori (Sacco+, 2008)
J/ApJ/722/1092 : Optical photometry of the ONC. II. (Da Rio+, 2010)
J/ApJ/722/1226 : IR photometry in λ Orionis cluster (Hernandez+, 2010)
J/MNRAS/411/435 : Stellar parameters and extinction (Bailer-Jones, 2011)
J/A+A/536/A63 : Collinder 69 very low mass stars & brown dwarfs (Bayo+, 2011)
J/A+A/547/A80 : Properties of Collinder 69 low-mass members (Bayo+, 2012)
J/ApJS/208/9 : Intrinsic colors & temperatures of PMS stars (Pecaut+, 2013)
J/AJ/150/100 : WISE YSO cand. near σ and λ Ori (Koenig+, 2015)
J/AJ/152/113 : Pleiades members with K2 LCs. I. Periods (Rebull+, 2016)
J/AJ/153/188 : Sp. of the foreground population in Orion A (Fang+, 2017)
J/ApJS/236/27 : APOGEE-2 survey of Orion Complex (OSFC). I. (Cottle+, 2018)
J/AJ/156/84 : APOGEE-2 survey of Orion Complex. II. (Kounkel+, 2018)
J/AJ/155/196 : K2 LCs for members of USco & ρ Oph (Rebull+, 2018)
J/ApJ/870/32 : Kinematics in young star clusters & assoc. (Kuhn+, 2019)
J/A+A/623/A159 : NGC6530 member param. from Gaia-ESO survey (Prisinzano+ 2019)
J/AJ/159/182 : APOGEE Net, YSOs param. through deep learning (Olney+, 2020)
J/ApJS/257/46 : Membership and rot. data for clusters (Godoy-Rivera+, 2021)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 28 A28 -- Name SIMBAD name
30- 40 F11.8 deg RAdeg [77.87/87.32] Right Ascension (J2000)
42- 52 F11.8 deg DEdeg [3.45/12.94] Declination (J2000)
54- 58 F5.3 [K] logTeff [3.4/4.5] log Effective Temperature
60- 64 F5.3 [K] e_logTeff [0.004/0.09]? Error in logTeff
66- 71 F6.3 [Rsun] logLstar [-2/4.7]? log luminosity
73- 77 F5.3 [Rsun] e_logLstar [0.02/1.1]? Error in logLstar
79- 83 F5.3 Msun Mstar [0.1/1.7]? Mass
85- 89 F5.3 Msun e_Mstar [0.007/0.3]? Error in Mstar
91- 95 F5.3 [yr] logAge [5.5/7.8]? log age
97-101 F5.3 [yr] e_logAge [0.004/0.5]? Error in logAge
103-108 F6.3 mag Av [-0.7/2.5]? Extinction
110-114 F5.3 mag e_Av [0.005/1.8]? Error in Av
116-118 A3 --- Class YSO Class ("II" or "III")
120-127 A8 --- Region Subregion in Lambda Orionis if any
("B30", "B35" or "LamOri-1")
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 14-Aug-2023