Exploring the Stellar Rotation of Early-type Stars in the LAMOST Medium-resolution Survey. I. Catalog

• Published in: The Astrophysical journal. Supplement series Vol. 257; no. 2; pp. 22 - 34
• Main Authors: Sun, Weijia, Duan, Xiao-Wei, Deng, Licai, de Grijs, Richard, Zhang, Bo, Liu, Chao
• Format: Journal Article
• Language: English
• Published: Saskatoon The American Astronomical Society 01.12.2021; IOP Publishing
• Subjects: A stars; Astronomical models; Astronomy data analysis; Early-type stars; Labels; Line spectra; Main sequence stars; Parameters; Signal to noise ratio; Sky surveys (astronomy); Spectral resolution; Spectroscopic telescopes; Spectroscopy; Stars; Stellar evolution; Stellar mass; Stellar models; Stellar properties; Stellar rotation
• ISSN: 0067-0049; 1538-4365
• DOI: 10.3847/1538-4365/ac1acf

Abstract We derive stellar parameters and abundances (“stellar labels”) of 40,034 late-B and A-type main-sequence stars extracted from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope Medium Resolution Survey (LAMOST–MRS). The primary selection of our early-type sample was obtained from LAMOST Data Release 7 based on spectral-line indices. We employed the Stellar Label Machine to derive their spectroscopic stellar parameters, drawing on Kurucz spectral synthesis models with 6000 < T eff < 15,000 K and −1 < [M/H] < 1 dex. For a signal-to-noise ratio of ∼60, the cross validated scatter is ∼75 K, 0.06 dex, 0.05 dex, and ∼3.5 km s −1 for T eff , log g , [M/H], and v sin i , respectively. A comparison with objects with prior known stellar labels shows great consistency for all stellar parameters, except for log g . Although this is an intrinsic caveat that comes from the MRS’s narrow wavelength coverage, it only has a minor effect on estimates of the stellar rotation rates because of the decent spectral resolution and the profile-fitting method employed. The masses and ages of our early-type sample stars were inferred from nonrotating stellar evolution models. This paves the way for reviewing the properties of stellar rotation distributions as a function of stellar mass and age.