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@article{1414058,
author = {Krtička, Jiří and Kubát, Jiří},
article_number = {duben},
doi = {http://dx.doi.org/10.1051/0004-6361/201731969},
keywords = {stars: winds outflows; stars: mass-loss; stars: early-type; Magellanic Clouds; hydrodynamics; radiative transfer},
language = {eng},
issn = {1432-0746},
journal = {Astronomy and Astrophysics},
title = {Global hot-star wind models for stars from Magellanic Clouds},
url = {https://www.aanda.org/articles/aa/abs/2018/04/aa31969-17/aa31969-17.html},
volume = {612},
year = {2018}
}
TY - JOUR
ID - 1414058
AU - Krtička, Jiří - Kubát, Jiří
PY - 2018
TI - Global hot-star wind models for stars from Magellanic Clouds
JF - Astronomy and Astrophysics
VL - 612
IS - duben
SP - "A20-1"-"A20-11"
EP - "A20-1"-"A20-11"
PB - EDP Sciences
SN - 14320746
KW - stars: winds outflows
KW - stars: mass-loss
KW - stars: early-type
KW - Magellanic Clouds
KW - hydrodynamics
KW - radiative transfer
UR - https://www.aanda.org/articles/aa/abs/2018/04/aa31969-17/aa31969-17.html
N2 - We provide mass-loss rate predictions for O stars from Large and Small Magellanic Clouds. We calculate global (unified, hydrodynamic) model atmospheres of main sequence, giant, and supergiant stars for chemical composition corresponding to Magellanic Clouds. The models solve radiative transfer equation in comoving frame, kinetic equilibrium equations (also known as NLTE equations), and hydrodynamical equations from (quasi-)hydrostatic atmosphere to expanding stellar wind. The models allow us to predict wind density, velocity, and temperature (consequently also the terminal wind velocity and the mass-loss rate) just from basic global stellar parameters. As a result of their lower metallicity, the line radiative driving is weaker leading to lower wind mass-loss rates with respect to the Galactic stars. We provide a formula that fits the mass-loss rate predicted by our models as a function of stellar luminosity and metallicity. On average, the mass-loss rate scales with metallicity as dMdt sim Z^0.59. The predicted mass-loss rates are lower than mass-loss rates derived from Halpha diagnostics and can be reconciled with observational results assuming clumping factor Cc = 9. On the other hand, the predicted mass-loss rates either agree or are slightly higher than the mass-loss rates derived from ultraviolet wind line profiles. The calculated P v ionization fractions also agree with values derived from observations for LMC stars with Teff < 40 000 K. Taken together, our theoretical predictions provide reasonable models with consistent mass-loss rate determination, which can be used for quantitative study of stars from Magellanic Clouds.
ER -
KRTIČKA, Jiří a Jiří KUBÁT. Global hot-star wind models for stars from Magellanic Clouds. \textit{Astronomy and Astrophysics}. EDP Sciences, 2018, roč.~612, duben, s.~''A20-1''-''A20-11'', 11 s. ISSN~1432-0746. Dostupné z: https://dx.doi.org/10.1051/0004-6361/201731969.
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