Modeling variability of Be stars

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F19%3A00107398" target="_blank" >RIV/00216224:14310/19:00107398 - isvavai.cz</a>

Result on the web

<a href="http://var.astro.cz/oejv/issues/oejv0197.pdf" target="_blank" >http://var.astro.cz/oejv/issues/oejv0197.pdf</a>

DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Modeling variability of Be stars

Original language description

Be stars are rapidly rotating non-supergiant B-type stars surrounded by equatorial Keplerian disks. The characteristic property of all Be stars is their multiperiodic variability driven for example by pulsations in isolated Be stars or by the effects of binarity. We assume in our models the equatorial decretion disk that stems from the angular momentum loss needed to keep the central object at or below the critical rotation. Using our hydrodynamic code, we calculate the 2D profile of Be stars’ disk structure under various physical and geometrical configurations of the star-disk system as well as various profiles of the circumstellar medium. The tidal interactions in binary systems facilitate the matter ejection from the equatorial region of the star, and there is also evidence of warping of the disk in binaries. The important subclass is the Be/X-ray binaries, consisting of a Be star and mostly a neutron star (NS), which belong to the brightest objects in the X-ray sky. Intensive matter accretion from the optical donor companion onto the compact object in a relatively close binary system produces transient phases of the high energy X-ray emission which dramatically vary in brightness and whose timescales may range from milliseconds to years. We calculate the effects of X-ray irradiation on the temperature structure of the Be stars’ disk. Using the Bondi-Hoyle-Littleton approximation, we estimate the NS accretion rate and the excess of X-ray luminosity during various phases of NS-disk interaction.

Czech name

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Czech description

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Type

D - Article in proceedings

CEP classification

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OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2019

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Article name in the collection

Proceedings of the 50thConference on Variable Stars Research

ISBN

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ISSN

1801-5964

e-ISSN

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Number of pages

7

Pages from-to

43-49

Publisher name

Open European Journal on Variable Stars

Place of publication

Neuveden

Event location

Brno

Event date

Nov 30, 2018

Type of event by nationality

EUR - Evropská akce

UT code for WoS article

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