Mass Distribution for Single-lined Hot Subdwarf Stars in LAMOST

0574936 - ASÚ 2024 RIV GB eng J - Článek v odborném periodiku
Lei, Z. - He, R. - Németh, Péter - Zou, X. - Xiao, H. - Yang, Y. - Zhao, J.
Mass Distribution for Single-lined Hot Subdwarf Stars in LAMOST.
Astrophysical Journal. Roč. 953, č. 2 (2023), č. článku 122. ISSN 0004-637X. E-ISSN 1538-4357
Grant CEP: GA ČR(CZ) GA22-34467S
Institucionální podpora: RVO:67985815
Klíčová slova: B subdwarf stars * stellar masses * spectral energy distribution
Obor OECD: Astronomy (including astrophysics,space science)
Impakt faktor: 4.9, rok: 2022
Způsob publikování: Open access

Masses for 664 single-lined hot subdwarf stars identified in LAMOST were calculated by comparing synthetic fluxes from spectral energy distribution with observed fluxes from a Virtual Observatory service. Three groups of hot subdwarf stars were selected from the whole sample according to their parallax precision to study the mass distributions. We found.that He-poor sdB/sdOB stars present a wide mass distribution from 0.1 to 1.0 M-circle dot with a sharp mass peak at around 0.46 M-circle dot, which is consistent with canonical binary model prediction. He-rich sdB/sdOB/sdO stars present a much flatter mass distribution than He-poor sdB/sdOB stars and with a mass peak at around 0.42 M-circle dot. By comparing the observed mass distributions to the predictions of different formation scenarios, we concluded that the binary merger channel, including two helium white dwarfs (He-WDs) and He-WD + mainsequence mergers, cannot be the only main formation channel for He-rich hot subdwarfs, and other formation channels, such as the surviving companions from Type Ia supernovae, could also make impacts on producing this special population, especially for He-rich hot subdwarfs with masses less than 0.44 M-circle dot. He-poor sdO stars also present a flatter mass distribution with an inconspicuous peak mass at 0.18 M-circle dot. The similar mass-Delta RVmax distribution between He-poor sdB/sdOB and sdO stars supports the scenario that He-poor sdO stars could be the subsequent evolution stage of He-poor sdB/sdOB stars.
Trvalý link: https://hdl.handle.net/11104/0345567