New mass-loss rates of B supergiants from global wind models

0548202 - ASÚ 2022 RIV FR eng J - Článek v odborném periodiku
Krtička, J. - Kubát, Jiří - Krtičková, I.
New mass-loss rates of B supergiants from global wind models.
Astronomy & Astrophysics. Roč. 647, March (2021), č. článku A28. ISSN 0004-6361. E-ISSN 1432-0746
Grant CEP: GA ČR(CZ) Ga18-05665S
Grant ostatní: Ministerstvo školství, mládeže a tělovýchovy - GA MŠk(CZ) LM2018140
Institucionální podpora: RVO:67985815
Klíčová slova: stars * winds * outflows
Obor OECD: Astronomy (including astrophysics,space science)
Impakt faktor: 6.240, rok: 2021
Způsob publikování: Open access s časovým embargem
https://doi.org/10.1051/0004-6361/202039900

Massive stars lose a significant fraction of mass during their evolution. However, the corresponding mass-loss rates are rather uncertain, especially for evolved stars. To improve this, we calculated global line-driven wind models for Galactic B supergiants. Our models predict radial wind structure and particularly the mass-loss rates and terminal velocities directly from basic stellar parameters. The hydrodynamic structure of the flow is consistently determined from the photosphere in nearly hydrostatic equilibrium to supersonically expanding wind. The radiative force is derived from the solution of the radiative transfer equation in the comoving frame. We provide a simple formula that predicts theoretical mass-loss rates as a function of stellar luminosity and effective temperature. The mass-loss rate of B supergiants slightly decreases with temperature down to about 22.5 kK, where the region of recombination of FeIV to FeIII starts to appear. In this region, which is about 5 kK wide, the mass-loss rate gradually increases by a factor of about 6. The increase of the mass-loss rate is associated with a gradual decrease of terminal velocities by a factor of about 2. We compared the predicted wind parameters with observations.
Trvalý link: http://hdl.handle.net/11104/0324307