Massive donors in interacting binaries: effect of metallicity
| Autor: | Alina G. Istrate, J. Klencki, Gijs Nelemans, Onno R. Pols |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Astronomy
Metallicity YELLOW SUPERGIANTS FOS: Physical sciences Context (language use) Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics Astronomy & Astrophysics Computer Science::Digital Libraries 01 natural sciences RADIATIVE OPACITIES general [binaries] massive [stars] BLUE Binary black hole Mass transfer 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics PRESUPERNOVA EVOLUTION SMALL-MAGELLANIC-CLOUD 010303 astronomy & astrophysics Solar and Stellar Astrophysics (astro-ph.SR) Astrophysics::Galaxy Astrophysics Physics First episode Science & Technology 010308 nuclear & particles physics Gravitational wave Astrophysics::Instrumentation and Methods for Astrophysics PARSEC EVOLUTIONARY TRACKS RED SUPERGIANT RATIO supergiants Astronomy and Astrophysics Physics::History of Physics WOLF-RAYET STARS Wolf-Rayet [stars] Stars gravitational waves Astrophysics - Solar and Stellar Astrophysics STELLAR EVOLUTION Space and Planetary Science evolution [stars] Physical Sciences Astrophysics::Earth and Planetary Astrophysics O-STARS Supergiant |
| Zdroj: | Astronomy & Astrophysics, 638, 1-19 Astronomy & Astrophysics, 638, pp. 1-19 |
| ISSN: | 1432-0746 |
| Popis: | Metallicity is known to significantly affect the radial expansion of a massive star: the lower the metallicity, the more compact the star, especially during its post-MS evolution. We study this effect in the context of binary evolution. Using the stellar-evolution code MESA, we computed evolutionary tracks of stars at different metallicities, exploring variations of factors known to affect the radial expansion (e.g. semiconvection, overshooting, rotation). We find observational support for an evolution in which already at metallicity $0.2Z_{\odot}$ massive stars remain relatively compact during the Hertzprung-Gap (HG) phase and most of their expansion occurs during core-helium burning (CHeB). Consequently, we show that metallicity has a strong influence on the type of mass transfer evolution in binary systems. At solar metallicity, a case-B mass transfer is initiated shortly after the end of MS, and a giant donor is almost always a rapidly expanding HG star. At lower metallicity, the parameter space for mass transfer from a more evolved CHeB star increases dramatically. This means that envelope stripping and formation of helium stars in low-metallicity environments occurs later in the evolution of the donor, implying a much shorter duration of the Wolf-Rayet phase (even by an order of magnitude) and higher final core masses. This metallicity effect is independent of the impact of metallicity-dependent stellar winds. At very low metallicities, a significant fraction of massive stars in binaries engages in the first episode of mass transfer very late into their evolution, when they already have a well-developed CO core. The remaining lifetime ($< 10^4$ yr) is unlikely to be enough to strip the entire H-rich envelope. We also briefly discuss the extremely small parameter space for mass transfer from massive convective-envelope donors in the context of binary black hole merger formation. 15 pages, 8 figures (+ 4 pages, 4 fig. appendix), to appear in A&A |
| Databáze: | OpenAIRE |
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