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

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F21%3A00118958" target="_blank" >RIV/00216224:14310/21:00118958 - isvavai.cz</a>

Alternative codes found

RIV/67985815:_____/21:00548202

Result on the web

<a href="https://doi.org/10.1051/0004-6361/202039900" target="_blank" >https://doi.org/10.1051/0004-6361/202039900</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/0004-6361/202039900" target="_blank" >10.1051/0004-6361/202039900</a>

Result language

angličtina

Original language name

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

Original language description

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. While the observed wind terminal velocities are reasonably reproduced by the models, the situation with mass-loss rates is less clear. The mass-loss rates derived from observations that are uncorrected for clumping are by a factor of 3 to 9 higher than our predictions on cool and hot sides of the studied sample, respectively. These observations can be reconciled with theory assuming a temperature-dependent clumping factor that is decreasing toward lower effective temperatures. On the other hand, the mass-loss rate estimates that are not sensitive to clumping agree with our predictions much better. Our predictions are by a factor of about 10 lower than the values currently used in evolutionary models appealing for reconsideration of the role of winds in the stellar evolution.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2021

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Astronomy and Astrophysics

ISSN

0004-6361

e-ISSN

1432-0746

Volume of the periodical

647

Issue of the periodical within the volume

March

Country of publishing house

FR - FRANCE

Number of pages

13

Pages from-to

„A28“

UT code for WoS article

000626173100001

EID of the result in the Scopus database

2-s2.0-85102031045