J/A+A/686/A269 Young Stellar Objects from LAMOST and ZTF surveys (Zhang+, 2024)
Young stellar objects from LAMOST and ZTF surveys:
Physical properties, classification and light curve analysis.
Zhang J.-Y., Zhang Y.-X., Kang Z.-H., Li C.-H., Zhao Y.-H.
<Astron. Astrophys. 686, A269 (2024)>
=2024A&A...686A.269Z 2024A&A...686A.269Z (SIMBAD/NED BibCode)
ADC_Keywords: YSOs ; Protostars ; Stars, variable ; Stars, pre-main sequence
Keywords: methods: data analysis - techniques: miscellaneous - catalogs -
stars: pre-main-sequence - stars: variables: general
Abstract:
The study of young stellar objects (YSOs) not only enhances our
understanding of star formation and stellar evolution, but also
contributes to broader areas of astrophysics, including planetary
science, galactic dynamics, and astrochemistry.
We aimed to comprehensively analyse 657 YSOs and provide their
physical parameter measurements using data from Zwicky Transient
Facility (ZTF) g- and r-band light curves and the Gaia, WISE, 2MASS,
and LAMOST databases. Specifically, we sought to identify periodicity
in the light curves and classify the YSOs based on the Q-M variability
plane, which enabled us to quantify flux asymmetry and
quasi-periodicity.
To achieve our objectives, we conducted a meticulous examination of
the light curves obtained from the ZTF and estimated the physical
parameters of the YSOs. These parameters were discerned by integrating
stellar model atmosphere grids, photometric data, Gaia DR3 parallaxes,
and pre-main-sequence evolutionary tracks. We employed the Q-M
variability plane to classify the YSOs and determine the presence of
periodic patterns. Additionally, we analysed the distribution of
variability slope angles in the colour-magnitude diagram (CMD) to
discern patterns associated with extinction-driven and
accretion-related variability.
Our analysis revealed significant findings regarding the variability
patterns and physical characteristics of the YSOs. Among the 657
objects analysed, 37 exhibited periodic variability and 2 displayed
multi-period behaviour. Furthermore, we identified distinct
variability patterns, including quasi-periodic symmetry,
quasi-periodic dipping, aperiodic dipping, bursting behaviour,
stochastic variability, and long-timescale variations. Notably, the
distribution of variability slope angles in the CMD varied between
dippers and bursters, indicating different underlying variability
drivers. Additionally, we observed that YSOs classified as classical T
Tauri stars and weak-line T Tauri stars exhibited contrasting light
curve characteristics, with Class II YSOs displaying asymmetry and
Class III YSOs showing (quasi-)periodic variations. These findings
underscore the importance of considering variability patterns when
classifying and determining the nature of YSOs.
Description:
We comprehensively analyse 657 YSOs and provide their physical
parameter measurement using data from the Zwicky Transient Facility
(ZTF)'s g and r-band light curves, Gaia, WISE, 2MASS, and LAMOST
databases. Specifically, we sought to identify periodicity in the
light curves and classify the YSOs based on the Q-M variability plane,
enabling us to quantify flux asymmetry and quasi-periodicity.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 162 342 Properties of our YSO sample
table5.dat 69 659 Light curve classification follows the Q and M
listsp.dat 46 335 List of spectra
sp/* . 335 Individual fits spectra
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See also:
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- --- [Gaia DR3]
10- 28 I19 --- GaiaDR3 Gaia DR3 designation
30- 39 F10.6 deg RAdeg Right Ascension (J2000) from ZTF
41- 50 F10.6 deg DEdeg Declination from (J2000) ZTF
52- 55 F4.2 --- Av The extinction
57- 60 F4.2 --- e_Av The error of the extinction
62- 65 I4 K Teff ? Stellar effective temperature
67- 70 I4 K E_Teff ? The upper error of Teff
73- 75 I3 K e_Teff ? The lower error of Teff
77- 81 F5.2 [Lsun] logL ? Stellar luminosity
83- 87 F5.2 [Lsun] E_logL ? The upper error of logL
90- 93 F4.2 [Lsun] e_logL ? The lower error of logL
95-100 F6.2 Myr Age ? The stellar age determined in this work
102-107 F6.2 Myr E_Age ? The upper error of age
110-114 F5.2 Myr e_Age ? The lower error of age
116-119 F4.2 Msun Mass ? The stellar mass determined in this work
121-125 F5.2 Msun E_Mass ? The upper error of mass
128-131 F4.2 Msun e_Mass ? The lower error of mass
133-139 F7.2 km/s EW The H-alpha equivalency width determined
in this work
141-144 F4.2 km/s e_EW The error of EW
146-151 F6.2 Msun/yr Mrate The Mass Accretion Rate determined
in this work
153-156 F4.2 Msun/yr e_Mrate The error of mrate
158-160 A3 --- Type Type (II or III) of the YSOs
162 A1 --- Class [CW] Class WTTS (W) or CTTS (C) of the YSOs
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- ZTF ZTF designation
14- 23 F10.6 deg RAdeg Right Ascension (J2000)
25- 33 F9.6 deg DEdeg Declination (J2000)
35- 38 A4 --- Type The Q-M type
40- 49 F10.6 d Period ? The lomb-scargle period
51- 59 F9.6 --- Q The quasi-periodicity statistics
61- 69 F9.6 --- M The flux asymmetry statistics
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Byte-by-byte Description of file: listsp.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- --- [Gaia DR3]
10- 28 I19 --- GaiaDR3 Gaia DR3 designation
30- 46 A17 --- FileName Name of the spectrum file in subdirectory sp
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Acknowledgements:
Jingyi Zhang, zhkang(at)bao.ac.cn
(End) Jingyi Zhang [NAOC, China], Patricia Vannier [CDS] 02-Apr-2024