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

J 2021

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

KRTIČKA, Jiří; Jiří KUBÁT a Iva KRTIČKOVÁ

Základní údaje

Originální název

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

Autoři

KRTIČKA, Jiří; Jiří KUBÁT a Iva KRTIČKOVÁ

Vydání

Astronomy and Astrophysics, EDP Sciences, 2021, 0004-6361

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10308 Astronomy

Stát vydavatele

Francie

Utajení

není předmětem státního či obchodního tajemství

Odkazy

URL

Impakt faktor

Impact factor: 6.240

Kód RIV

RIV/00216224:14310/21:00118958

Organizační jednotka

Přírodovědecká fakulta

DOI

https://doi.org/10.1051/0004-6361/202039900

UT WoS

000626173100001

EID Scopus

2-s2.0-85102031045

Klíčová slova anglicky

stars: winds; outflows; stars: mass-loss; stars: early-type; supergiants; hydrodynamics

Štítky

14312040, rivok

Příznaky

Mezinárodní význam, Recenzováno

Změněno: 6. 5. 2021 12:38, Mgr. Marie Novosadová Šípková, DiS.

Anotace

V originále

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.

Návaznosti

GA18-05665S, projekt VaV

Název: Ztráta hmoty v pozdních fázích vývoje hmotných hvězd

Investor: Grantová agentura ČR, Ztráta hmoty v pozdních fázích vývoje hmotných hvězd

LM2018140, projekt VaV

Název: e-Infrastruktura CZ (Akronym: e-INFRA CZ)

Investor: Ministerstvo školství, mládeže a tělovýchovy ČR, e-Infrastruktura CZ

Citovat

KRTIČKA, Jiří; Jiří KUBÁT a Iva KRTIČKOVÁ. New mass-loss rates of B supergiants from global wind models. Astronomy and Astrophysics. EDP Sciences, 2021, roč. 647, March, s. "A28", 13 s. ISSN 0004-6361. Dostupné z: https://doi.org/10.1051/0004-6361/202039900.

@article{1766197,
   author = {Krtička, Jiří and Kubát, Jiří and Krtičková, Iva},
   article_number = {March},
   doi = {https://doi.org/10.1051/0004-6361/202039900},
   keywords = {stars: winds; outflows; stars: mass-loss; stars: early-type; supergiants; hydrodynamics},
   language = {eng},
   issn = {0004-6361},
   journal = {Astronomy and Astrophysics},
   title = {New mass-loss rates of B supergiants from global wind models},
   url = {https://doi.org/10.1051/0004-6361/202039900},
   volume = {647},
   year = {2021}
}

TY  - JOUR
ID  - 1766197
AU  - Krtička, Jiří - Kubát, Jiří - Krtičková, Iva
PY  - 2021
TI  - New mass-loss rates of B supergiants from global wind models
JF  - Astronomy and Astrophysics
VL  - 647
IS  - March
SP  - "A28"
EP  - "A28"
PB  - EDP Sciences
SN  - 00046361
KW  - stars: winds
KW  - outflows
KW  - stars: mass-loss
KW  - stars: early-type
KW  - supergiants
KW  - hydrodynamics
UR  - https://doi.org/10.1051/0004-6361/202039900
N2  - 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.
ER  -

KRTIČKA, Jiří; Jiří KUBÁT a Iva KRTIČKOVÁ. New mass-loss rates of B supergiants from global wind models. \textit{Astronomy and Astrophysics}. EDP Sciences, 2021, roč.~647, March, s.~''A28'', 13 s. ISSN~0004-6361. Dostupné z: https://doi.org/10.1051/0004-6361/202039900.

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