Hot subdwarf stars from Gaia DR2 & LAMOST DR6+7. I.

DOI

182 single-lined hot subdwarf stars are identified by using spectra from the sixth and seventh data releases (DR6 and DR7) of the Large Sky Area Multi-Object Fibre Spectroscopic Telescope survey. We classified all the hot subdwarf stars using a canonical classification scheme, and got 89 sdB, 37 sdOB, 26 sdO, 24 He-sdOB, 3 He-sdO, and 3 He-sdB stars, respectively. Among these stars, 108 hot subdwarfs are newly discovered, while 74 stars were reported by previous catalogs. The atmospheric parameters of these stars were obtained by fitting the hydrogen (H) and helium (He) lines with non-local thermodynamic equilibrium model atmospheres. The atmospheric parameters confirm the two He sequences and the two subgroups of He-sdOB stars in our samples, which were found by previous studies in the T_eff_-log(nHe/nH) diagram. Our results demonstrate different origins of field hot subdwarf stars and extreme horizontal branch stars in globular clusters, and provide strict observational limits on the formation and evolution models of the different sub-types of these evolved objects. Based on the results, we evaluated the completeness of the Geier+ (2017, J/A+A/600/A50) catalog. We found the fraction of hot subwarf stars is between 10% and 60%, depending on the brightness of the sample. A more accurate estimation for the hot subdwarf fraction can be obtained when similar results from composite spectra will become available.

Cone search capability for table J/ApJ/889/117/table1 (Information on the 182 hot subdwarf stars identified in this study)

Identifier
DOI http://doi.org/10.26093/cds/vizier.18890117
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/ApJ/889/117
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/889/117
Related Identifier http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/889/117
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/ApJ/889/117
Provenance
Creator Lei Z.; Zhao J.; Nemeth P.; Zhao G.
Publisher CDS
Publication Year 2021
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Interdisciplinary Astronomy; Natural Sciences; Physics; Stellar Astronomy