Extremely Low-mass White Dwarf Stars Observed in Gaia DR2 and LAMOST DR8

We present the first results from our ongoing project to study extremely low-mass (ELM) white dwarfs (WDs) ( M ≤ 0.3 M ☉ ) with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) spectra. Based on the LAMOST DR8 spectral database, we analyzed 136 ELM WD candidates selected from G...

Full description

Saved in:
Bibliographic Details
Published in:The Astrophysical journal 2022-09, Vol.936 (1), p.5
Main Authors: Wang, Kun, Németh, Péter, Luo, Yangping, Chen, Xiaodian, Jiang, Qingquan, Cao, Xingmei
Format: Article
Language:English
Subjects:
Astrophysics
Binary systems
Compact objects
Dwarf stars
Parallax
Parameter identification
Radial velocity
Spectra
Spectroscopic telescopes
White dwarf stars
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We present the first results from our ongoing project to study extremely low-mass (ELM) white dwarfs (WDs) ( M ≤ 0.3 M ☉ ) with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) spectra. Based on the LAMOST DR8 spectral database, we analyzed 136 ELM WD candidates selected from Gaia DR2 data and 12 known objects previously identified by the ELM Survey. The atmospheric parameters and radial velocities of these stars were obtained by fitting the LAMOST low-resolution spectra. After comparing the atmospheric parameters of the 12 known objects from this work to the results reported by the ELM Survey, we demonstrated the potential of LAMOST spectra in probing into the nature of ELM WDs. Based on the atmospheric parameters and Gaia EDR3 data, we identified 21 new high-probability ELM WDs with masses M ≤ 0.3 M ☉ and parallax estimates that agree to within a factor of 3. Two of them, J0338+4134 and J1129+4715, show significant radial velocity variability and are very likely to be binary systems containing at least one ELM WD.
ISSN:0004-637X
1538-4357
DOI:10.3847/1538-4357/ac847c