Extremely Low-mass White Dwarf Stars Observed in Gaia DR2 and LAMOST DR8
Extremely Low-mass White Dwarf Stars Observed in Gaia DR2 and LAMOST DR8
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DOI：
10.3847/1538-4357/ac847c
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发表时间：
2022-07
期刊：
影响因子：
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通讯作者：
K. Wang 王;P. N'emeth;Y. Luo 罗;X. Chen 陈;Q. Jiang 蒋;Xingmei 星梅 Cao 曹
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文献类型：
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作者：
K. Wang 王;P. N'emeth;Y. Luo 罗;X. Chen 陈;Q. Jiang 蒋;Xingmei 星梅 Cao 曹
我们展示了我们正在进行的项目的第一个结果，研究极低质量（ELM）白矮星（WDs） （M≤0.3M☉）与大天空区域多目标光纤光谱望远镜（LAMOST）光谱。基于LAMOST DR8光谱数据库，我们分析了从Gaia DR2数据中选择的136个ELM WD候选者和ELM Survey之前确定的12个已知物体。通过拟合LAMOST低分辨率光谱得到了这些恒星的大气参数和径向速度。通过与ELM调查报告的12个已知天体的大气参数进行比较，我们证明了LAMOST光谱在探索ELM WDs性质方面的潜力。基于大气参数和盖亚EDR3数据，我们确定了21个新的高概率ELM WDs，质量M≤0.3M☉，视差估计在3因子内一致。其中两个，J0338+4134和J1129+4715，显示出显著的径向速度变化，很可能是包含至少一个ELM WD的双星系统。
We present the first results from our ongoing project to study extremely low-mass (ELM) white dwarfs (WDs) (M ≤ 0.3M ☉) 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 ≤ 0.3M ☉ 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.