Volume-limited sample of low-mass red giant stars, the progenitors of hot subdwarf stars. l. Sample selection and binary classification method

0567510 - ASÚ 2023 RIV FR eng J - Článek v odborném periodiku
Uzundag, M. - Jones, M. I. - Vučković, M. - Vos, Joris - Bobrick, A. - Paladini, G.
Volume-limited sample of low-mass red giant stars, the progenitors of hot subdwarf stars. l. Sample selection and binary classification method.
Astronomy & Astrophysics. Roč. 668, December (2022), č. článku A89. ISSN 0004-6361. E-ISSN 1432-0746
Grant CEP: GA ČR(CZ) GA22-34467S
Institucionální podpora: RVO:67985815
Klíčová slova: low-mass stars * subdwarfs * late-type stars
Obor OECD: Astronomy (including astrophysics,space science)
Impakt faktor: 6.5, rok: 2022
Způsob publikování: Open access

We perform a spectroscopic survey to find binary systems that include low-mass red giants near the tip of the RGB, which are predicted to be the direct progenitors of subdwarf B (sdB) stars. We aim to obtain a homogeneous sample to search for the observational evidence of correlations between the key parameters governing the formation of sdB stars and constrain the physics of stable mass transfer.
Methods: Based on data from the Gaia mission and several ground-based, multiband photometry surveys, we compiled a sample of low-mass red giant branch (RGB) candidates. The candidates were selected according to their Gaia data release 2 (DR2) color, absolute magnitude, and proper motion cuts. In this work, we concentrated on the southern hemisphere targets and conducted a spectroscopic survey of 88 red giant stars to search for the long-period RGB plus main-sequence binary systems within 200 pc. Combining radial velocity (RV) measurements from ground-based observations with CORALIE and RV measurements from Gaia DR2 and from the early data release 3 (eDR3) as well as the astrometric excess noise and renormalized unit weight error measurements from Gaia DR3, we defined a robust binary classification method. In addition, we searched for known binary systems in the literature and in Gaia DR3.
Trvalý link: https://hdl.handle.net/11104/0338764