Polarization of light from fast-rotating Wolf-Rayet stars:
Monte Carlo simulations compared to the analytical formula

J 2025

Polarization of light from fast-rotating Wolf-Rayet stars: Monte Carlo simulations compared to the analytical formula

ABDELLAOUI, Slah; Jiří KRTIČKA; Brankica KUBATOVA a Petr KURFÜRST

Základní údaje

Originální název

Polarization of light from fast-rotating Wolf-Rayet stars: Monte Carlo simulations compared to the analytical formula

Autoři

ABDELLAOUI, Slah; Jiří KRTIČKA; Brankica KUBATOVA a Petr KURFÜRST

Vydání

Astronomy and Astrophysics, EDP Sciences, 2025, 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: 5.800 v roce 2024

Označené pro přenos do RIV

Ano

Kód RIV

RIV/00216224:14310/25:00141857

Organizační jednotka

Přírodovědecká fakulta

Klíčová slova anglicky

gamma-ray burst: general; stars: massive; stars: mass-loss; stars: rotation; stars: winds; outflows; stars: Wolf-Rayet

Štítky

14312040, rivok

Příznaky

Mezinárodní význam, Recenzováno

Změněno: 28. 8. 2025 15:24, Mgr. Marie Novosadová Šípková, DiS.

Anotace

V originále

Context. Fast-rotating Wolf-Rayet (WR) stars are potential progenitors of long gamma-ray bursts, but observational verification is challenging. Spectral lines from their expanding stellar wind obscure accurate rotational velocity measurements. Intrinsic polarization from wind rotation may help to determine rotational speeds. However, this procedure requires precise wind models. Aims. Our study aims to investigate the intrinsic polarization due to the rotational distortion of WR winds considering multiplescattering of photons and compare it to a single-scattering model, in which we use an analytical expression of the polarization. Methods. We studied the polarization signatures resulting from the prolate structure of rotating winds of two WR stars using a 3D Monte Carlo radiative transfer code Hyperion. We estimated the intrinsic polarization resulting from multiple-scattering in WR winds for different rotational velocities, inclination angles, and mass-loss rates. Results. Our results indicate that at a rotation rate of less than 50% of the critical rate, the intrinsic polarization from multiplescattering is close to that of a single-scattering model. However, at higher rotation velocities, the polarization from multiple-scattering increases with inclination up to 40 degrees, while it decreases for inclinations higher than about 60 degrees. This dependence is inconsistent with the single-scattering model. We also discuss the effect of the mass-loss rate on the polarization and find that the polarization changes linearly with the mass-loss rate. However, it is important to note that the relationship between polarization and mass-loss rate may vary for different types of stars. Conclusions. The results have implications for future studies of stellar winds and mass loss and may help to improve our understanding of the complex environments of massive stars. Our research offers valuable information on the complex polarization patterns observed in stellar winds, emphasizing the significance of accounting for the influence of multiple-scattering when interpreting observations.

Návaznosti

GA25-15910S, projekt VaV

Název: Větry horkých hvězd: řešení nejistot ztráty hmoty v blízkosti Eddingtonovy limity

Investor: Grantová agentura ČR, Větry horkých hvězd: řešení nejistot ztráty hmoty v blízkosti Eddingtonovy limity

90254, velká výzkumná infrastruktura

Název: e-INFRA CZ II

Přiložené soubory

2514143.pdf

Citovat

ABDELLAOUI, Slah; Jiří KRTIČKA; Brankica KUBATOVA a Petr KURFÜRST. Polarization of light from fast-rotating Wolf-Rayet stars: Monte Carlo simulations compared to the analytical formula. Astronomy and Astrophysics. EDP Sciences, 2025, roč. 698, May, s. "A225", 6 s. ISSN 0004-6361. Dostupné z: https://doi.org/10.1051/0004-6361/202553921.

@article{2514143,
   author = {Abdellaoui, Slah and Krtička, Jiří and Kubatova, Brankica and Kurfürst, Petr},
   article_number = {May},
   doi = {https://doi.org/10.1051/0004-6361/202553921},
   keywords = {gamma-ray burst: general; stars: massive; stars: mass-loss; stars: rotation; stars: winds; outflows; stars: Wolf-Rayet},
   language = {eng},
   issn = {0004-6361},
   journal = {Astronomy and Astrophysics},
   title = {Polarization of light from fast-rotating Wolf-Rayet stars: Monte Carlo simulations compared to the analytical formula},
   url = {https://doi.org/10.1051/0004-6361/202553921},
   volume = {698},
   year = {2025}
}

TY  - JOUR
ID  - 2514143
AU  - Abdellaoui, Slah - Krtička, Jiří - Kubatova, Brankica - Kurfürst, Petr
PY  - 2025
TI  - Polarization of light from fast-rotating Wolf-Rayet stars: Monte Carlo simulations compared to the analytical formula
JF  - Astronomy and Astrophysics
VL  - 698
IS  - May
SP  - "A225"
EP  - "A225"
PB  - EDP Sciences
SN  - 00046361
KW  - gamma-ray burst: general
KW  - stars: massive
KW  - stars: mass-loss
KW  - stars: rotation
KW  - stars: winds
KW  - outflows
KW  - stars: Wolf-Rayet
UR  - https://doi.org/10.1051/0004-6361/202553921
N2  - Context. Fast-rotating Wolf-Rayet (WR) stars are potential progenitors of long gamma-ray bursts, but observational verification is challenging. Spectral lines from their expanding stellar wind obscure accurate rotational velocity measurements. Intrinsic polarization from wind rotation may help to determine rotational speeds. However, this procedure requires precise wind models. Aims. Our study aims to investigate the intrinsic polarization due to the rotational distortion of WR winds considering multiplescattering of photons and compare it to a single-scattering model, in which we use an analytical expression of the polarization. Methods. We studied the polarization signatures resulting from the prolate structure of rotating winds of two WR stars using a 3D Monte Carlo radiative transfer code Hyperion. We estimated the intrinsic polarization resulting from multiple-scattering in WR winds for different rotational velocities, inclination angles, and mass-loss rates. Results. Our results indicate that at a rotation rate of less than 50% of the critical rate, the intrinsic polarization from multiplescattering is close to that of a single-scattering model. However, at higher rotation velocities, the polarization from multiple-scattering increases with inclination up to 40 degrees, while it decreases for inclinations higher than about 60 degrees. This dependence is inconsistent with the single-scattering model. We also discuss the effect of the mass-loss rate on the polarization and find that the polarization changes linearly with the mass-loss rate. However, it is important to note that the relationship between polarization and mass-loss rate may vary for different types of stars. Conclusions. The results have implications for future studies of stellar winds and mass loss and may help to improve our understanding of the complex environments of massive stars. Our research offers valuable information on the complex polarization patterns observed in stellar winds, emphasizing the significance of accounting for the influence of multiple-scattering when interpreting observations.
ER  -

ABDELLAOUI, Slah; Jiří KRTIČKA; Brankica KUBATOVA a Petr KURFÜRST. Polarization of light from fast-rotating Wolf-Rayet stars: Monte Carlo simulations compared to the analytical formula. \textit{Astronomy and Astrophysics}. EDP Sciences, 2025, roč.~698, May, s.~''A225'', 6 s. ISSN~0004-6361. Dostupné z: https://doi.org/10.1051/0004-6361/202553921.

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