J 2024

Unveiling stellar aurorae: simulating auroral emission lines in hot stars induced by high-energy irradiation

KAJAN, Michal; Jiří KRTIČKA a Jiří KUBÁT

Základní údaje

Originální název

Unveiling stellar aurorae: simulating auroral emission lines in hot stars induced by high-energy irradiation

Autoři

KAJAN, Michal (703 Slovensko, domácí); Jiří KRTIČKA (203 Česká republika, domácí) a Jiří KUBÁT (203 Česká republika)

Vydání

Monthly Notices of the Royal Astronomical Society, Oxford University Press, 2024, 0035-8711

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10308 Astronomy

Stát vydavatele

Velká Británie a Severní Irsko

Utajení

není předmětem státního či obchodního tajemství

Odkazy

Impakt faktor

Impact factor: 4.800 v roce 2023

Kód RIV

RIV/00216224:14310/24:00137715

Organizační jednotka

Přírodovědecká fakulta

UT WoS

001231710600006

EID Scopus

2-s2.0-85194484314

Klíčová slova anglicky

radiative transfer; software: simulations; stars: atmospheres; stars: early-type; stars: emission-line; Be; stars: magnetic fields

Štítky

Příznaky

Mezinárodní význam, Recenzováno
Změněno: 21. 11. 2024 11:17, Mgr. Marie Novosadová Šípková, DiS.

Anotace

V originále

Auroral emission lines result from the interaction between magnetic field and stellar wind, offering valuable insights into physical properties and processes occurring within magnetospheres of celestial bodies. While extensively studied in planetary and exoplanetary atmospheres, in ultracool dwarfs, and as radio emission from early-type stars, the presence of specific auroral emission lines in hot star spectra remains unexplored. In this study, we utilized tlusty code to simulate the auroral lines, while modelling the effect of the interaction between stellar wind and magnetosphere through X-ray irradiation. Utilizing high-resolution synthetic spectra generated from model atmospheres, we identified potential candidate lines indicative of auroral emission, which were absent in non-irradiated spectra. Emission lines in synthetic spectra were present primarily in the infrared domain. The most prominent line generated by irradiation was He ii 69458 & Aring;, which appeared in all our model atmospheres with effective temperatures ranging from 15 kK to 30 kK. We also calculated the minimum irradiation required to detect emission in this most prominent line. The presence of emission lines was interpreted by considering changes in the population of different excited states of given atoms. Besides the appearance of infrared emission lines, high-energy irradiation causes infrared excess. To complement our simulations, we also searched for auroral lines in Far Ultraviolet Spectroscopic Explorer (FUSE) observations, which are deposited in the Multimission Archive at Space Telescope catalogue. The comparison of observed spectra with synthetic spectra did not identify any possible candidate emission lines in FUSE spectra.