The orbital period-mass ratio relation of wide sdB plus MS binaries and its application to the stability of RLOF
- Wide binaries with hot subdwarf-B (sdB) primaries and main sequence companions are thought to form only through stable Roche-lobe overflow (RLOF) of the sdB progenitor near the tip of the red giant branch (RGB). We present the orbital parameters of 11 new long-period composite sdB binaries based on spectroscopic observations obtained with the UVES, FEROS, and CHIRON spectrographs. Using all wide sdB binaries with known orbital parameters, 23 systems, the observed period distribution is found to match very well with theoretical predictions. A second result is the strong correlation between the orbital period (P) and the mass ratio (q) in the observed wide sdB binaries. In the P-q plane two distinct groups emerge, with the main group (18 systems) showing a strong correlation of lower mass ratios at longer orbital periods. The second group comprises systems that are thought to be formed from higher mass progenitors. Based on theoretical models, a correlation between the initial mass ratio at the start of RLOF and core mass of the sdBWide binaries with hot subdwarf-B (sdB) primaries and main sequence companions are thought to form only through stable Roche-lobe overflow (RLOF) of the sdB progenitor near the tip of the red giant branch (RGB). We present the orbital parameters of 11 new long-period composite sdB binaries based on spectroscopic observations obtained with the UVES, FEROS, and CHIRON spectrographs. Using all wide sdB binaries with known orbital parameters, 23 systems, the observed period distribution is found to match very well with theoretical predictions. A second result is the strong correlation between the orbital period (P) and the mass ratio (q) in the observed wide sdB binaries. In the P-q plane two distinct groups emerge, with the main group (18 systems) showing a strong correlation of lower mass ratios at longer orbital periods. The second group comprises systems that are thought to be formed from higher mass progenitors. Based on theoretical models, a correlation between the initial mass ratio at the start of RLOF and core mass of the sdB progenitor is found, which defines a mass-ratio range at which RLOF is stable on the RGB.…
| Author details: | Joris VosORCiD, Maja Vuckovic, Xuefei Chen, Zhanwen Han, Thomas Boudreaux, Brad N. BarlowORCiD, Roy Ostensen, Péter NémethORCiDGND |
|---|---|
| DOI: | https://doi.org/10.1093/mnras/sty3017 |
| ISSN: | 0035-8711 |
| ISSN: | 1365-2966 |
| Title of parent work (English): | Monthly notices of the Royal Astronomical Society |
| Publisher: | Oxford Univ. Press |
| Place of publishing: | Oxford |
| Publication type: | Article |
| Language: | English |
| Date of first publication: | 2018/11/10 |
| Publication year: | 2018 |
| Release date: | 2021/04/12 |
| Tag: | binaries: spectroscopic; stars: evolution; stars: fundamental parameters; subdwarfs |
| Volume: | 482 |
| Issue: | 4 |
| Number of pages: | 14 |
| First page: | 4592 |
| Last Page: | 4605 |
| Funding institution: | Fondo Nacional de DesarrolloCientifico y Technologico (FONDECYT)Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT)CONICYT FONDECYT [3160504]; Natural Science Foundation of ChinaNational Natural Science Foundation of China [11733008, 11521303]; Yunnan province [2017HC018]; High Point University; European Organisation for Astronomical Research in the Southern Hemisphere under ESO programmes [088.D-0364(A), 093.D-0629(A), 096.D-0180(A), 097.D-0110(A), 098.D-0018(A), 099.D-0014(A), 099.A-9019(A), 0100.D-0082(A)]; CTIO/SMARTS 1.5-m telescope through the CNTAC [CN2018A-23] |
| Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Physik und Astronomie |
| DDC classification: | 5 Naturwissenschaften und Mathematik / 52 Astronomie / 520 Astronomie und zugeordnete Wissenschaften |
| Peer review: | Referiert |
| Publishing method: | Open Access / Green Open-Access |
