Результаты исследований: Публикации в книгах, отчётах, сборниках, трудах конференций › статья в сборнике материалов конференции › научная › Рецензирование
A nature of the X-ray and optical emission from gamma Cassiopeia stars. / Холтыгин, Александр Федорович; Якунин, Илья Андреевич; Рыспаева, Елизавета Борисовна; Мокшин, Дмитрий Николаевич.
Modern Astronomy: From the Early Universe to Exoplanets and Black Holes (VAK2024). Nizhny Arkhyz, Russian Federation : САО РАН, 2024. стр. 402-408.Результаты исследований: Публикации в книгах, отчётах, сборниках, трудах конференций › статья в сборнике материалов конференции › научная › Рецензирование
}
TY - GEN
T1 - A nature of the X-ray and optical emission from gamma Cassiopeia stars
AU - Холтыгин, Александр Федорович
AU - Якунин, Илья Андреевич
AU - Рыспаева, Елизавета Борисовна
AU - Мокшин, Дмитрий Николаевич
N1 - 2024maeu.conf..402K
PY - 2024/12
Y1 - 2024/12
N2 - To test the origin of the X-ray and optical emission from the gamma Cas-type stars, we analyzed their optical spectra obtained on the 6-m telescope BTA, the 1.25-m telescope of the Crimean station of the State Astronomical Institute (SAI, Moscow), the 2.5-m telescope SAI25 of SAI, and the photometric TESS light curves. We compare the optical variability of the γ Cas-type stars with variations of their X-ray luminosity. An overlap between the periods of line profile variations in the spectra of gamma Cas stars and the variations in their X-ray brightness allows us to assume that a significant fraction of X-rays emits from the same place where the optical radiation comes from. The gamma Cas-type stars HD45314, HD45995 and NGC6649 9 demonstrate the ultrafast X-ray brightness variations with the periods of about 50–90 seconds, which may be the rotation periods of white dwarfs components of binary systems. Thus, we can assume that at least for these stars the X-ray emission goes partly due to accretion onto rapidly rotating white dwarfs. The anomalously hard X-ray emission from the gamma Cas stars can be interpreted by assuming that the contribution of non-thermal X-ray emission is generated as a result of a reconnection of the local magnetic field lines of the Be star and its decretion disk.
AB - To test the origin of the X-ray and optical emission from the gamma Cas-type stars, we analyzed their optical spectra obtained on the 6-m telescope BTA, the 1.25-m telescope of the Crimean station of the State Astronomical Institute (SAI, Moscow), the 2.5-m telescope SAI25 of SAI, and the photometric TESS light curves. We compare the optical variability of the γ Cas-type stars with variations of their X-ray luminosity. An overlap between the periods of line profile variations in the spectra of gamma Cas stars and the variations in their X-ray brightness allows us to assume that a significant fraction of X-rays emits from the same place where the optical radiation comes from. The gamma Cas-type stars HD45314, HD45995 and NGC6649 9 demonstrate the ultrafast X-ray brightness variations with the periods of about 50–90 seconds, which may be the rotation periods of white dwarfs components of binary systems. Thus, we can assume that at least for these stars the X-ray emission goes partly due to accretion onto rapidly rotating white dwarfs. The anomalously hard X-ray emission from the gamma Cas stars can be interpreted by assuming that the contribution of non-thermal X-ray emission is generated as a result of a reconnection of the local magnetic field lines of the Be star and its decretion disk.
KW - Stars
KW - emission-line,
KW - Be stars
KW - X-rays
M3 - Conference contribution
SP - 402
EP - 408
BT - Modern Astronomy: From the Early Universe to Exoplanets and Black Holes (VAK2024)
PB - САО РАН
CY - Nizhny Arkhyz, Russian Federation
Y2 - 25 August 2024 through 31 August 2024
ER -
ID: 135909912