KRTIČKA, Jiří a Achim FELDMEIER. Stochastic light variations in hot stars from wind instability: finding photometric signatures and testing against the TESS data. Astronomy and Astrophysics. EDP Sciences, roč. 648, April, s. "A79", 9 s. ISSN 0004-6361. doi:10.1051/0004-6361/202040148. 2021.
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Základní údaje
Originální název Stochastic light variations in hot stars from wind instability: finding photometric signatures and testing against the TESS data
Autoři KRTIČKA, Jiří (203 Česká republika, garant, domácí) a Achim FELDMEIER.
Vydání Astronomy and Astrophysics, EDP Sciences, 2021, 0004-6361.
Další údaje
Originální jazyk angličtina
Typ výsledku Článek v odborném periodiku
Obor 10308 Astronomy
Stát vydavatele Francie
Utajení není předmětem státního či obchodního tajemství
WWW URL
Impakt faktor Impact factor: 6.240
Kód RIV RIV/00216224:14310/21:00118998
Organizační jednotka Přírodovědecká fakulta
Doi http://dx.doi.org/10.1051/0004-6361/202040148
UT WoS 000647070100001
Klíčová slova anglicky stars: winds; outflows; stars: mass-loss; stars: early-type; hydrodynamics; instabilities; stars: variables: general
Štítky rivok
Příznaky Mezinárodní význam, Recenzováno
Změnil Změnila: Mgr. Marie Šípková, DiS., učo 437722. Změněno: 3. 6. 2021 09:26.
Anotace
Context. Line-driven wind instability is expected to cause small-scale wind inhomogeneities, X-ray emission, and wind line profile variability. The instability can already develop around the sonic point if it is initiated close to the photosphere due to stochastic turbulent motions. In such cases, it may leave its imprint on the light curve as a result of wind blanketing.Aims. We study the photometric signatures of the line-driven wind instability.Methods. We used line-driven wind instability simulations to determine the wind variability close to the star. We applied two types of boundary perturbations: a sinusoidal one that enables us to study in detail the development of the instability and a stochastic one given by a Langevin process that provides a more realistic boundary perturbation. We estimated the photometric variability from the resulting mass-flux variations. The variability was simulated assuming that the wind consists of a large number of independent conical wind sectors. We compared the simulated light curves with TESS light curves of OB stars that show stochastic variability.Results. We find two typical signatures of line-driven wind instability in photometric data: a knee in the power spectrum of magnitude fluctuations, which appears due to engulfment of small-scale structure by larger structures, and a negative skewness of the distribution of fluctuations, which is the result of spatial dominance of rarefied regions. These features endure even when combining the light curves from independent wind sectors.Conclusions. The stochastic photometric variability of OB stars bears certain signatures of the line-driven wind instability. The distribution function of observed photometric data shows negative skewness and the power spectra of a fraction of light curves exhibit a knee. This can be explained as a result of the line-driven wind instability triggered by stochastic base perturbations.
Návaznosti
GA18-05665S, projekt VaVNázev: Ztráta hmoty v pozdních fázích vývoje hmotných hvězd
Investor: Grantová agentura ČR, Ztráta hmoty v pozdních fázích vývoje hmotných hvězd
VytisknoutZobrazeno: 28. 3. 2024 09:11