Mass and Angular Momentum Loss of B[e] Stars via Decretion Disks

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F17%3A00094660" target="_blank" >RIV/00216224:14310/17:00094660 - isvavai.cz</a>

Výsledek na webu

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DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Mass and Angular Momentum Loss of B[e] Stars via Decretion Disks

Popis výsledku v původním jazyce

We study the disks of B[e] stars assuming that the disks stem from the angular momentum loss from the central object. The angular momentum loss may be induced either by evolution of the stellar interior of critically rotating star or by merger event in a binary. In contrast to the usual stellar wind mass loss set by driving from the stellar luminosity, such decretion-disk mass loss is determined by the angular momentum loss needed to keep the central object in equilibrium. The angular momentum loss is given either by the interior evolution and decline in the star's moment of inertia, or by excess angular momentum present in a merging binary. Because the specific angular momentum in a Keplerian disk increases with the square root of the radius, the decretion mass loss associated with a required level of angular momentum loss depends crucially on the outer radius for viscous coupling of the disk. The magnetorotational instability can be the source of anomalous viscosity in decretion disks. The instability operates close to the star and disappears in the region where the disk orbital velocity is roughly equal to the sound speed. We study the differences between Be and B[e] star disks and discuss the reasons why stars of the stellar type B have disks, while other stars do not.

Název v anglickém jazyce

Mass and Angular Momentum Loss of B[e] Stars via Decretion Disks

Popis výsledku anglicky

We study the disks of B[e] stars assuming that the disks stem from the angular momentum loss from the central object. The angular momentum loss may be induced either by evolution of the stellar interior of critically rotating star or by merger event in a binary. In contrast to the usual stellar wind mass loss set by driving from the stellar luminosity, such decretion-disk mass loss is determined by the angular momentum loss needed to keep the central object in equilibrium. The angular momentum loss is given either by the interior evolution and decline in the star's moment of inertia, or by excess angular momentum present in a merging binary. Because the specific angular momentum in a Keplerian disk increases with the square root of the radius, the decretion mass loss associated with a required level of angular momentum loss depends crucially on the outer radius for viscous coupling of the disk. The magnetorotational instability can be the source of anomalous viscosity in decretion disks. The instability operates close to the star and disappears in the region where the disk orbital velocity is roughly equal to the sound speed. We study the differences between Be and B[e] star disks and discuss the reasons why stars of the stellar type B have disks, while other stars do not.

Druh

D - Stať ve sborníku

CEP obor

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OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

<a href="/cs/project/GA13-10589S" target="_blank" >GA13-10589S: Ztráta hmoty horkých hmotných hvězd</a><br>

Návaznosti

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

Rok uplatnění

2017

Kód důvěrnosti údajů

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

Název statě ve sborníku

B[e] Phenomenom: Forty Years of Studies

ISBN

9781583819005

ISSN

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e-ISSN

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Počet stran výsledku

5

Strana od-do

73-77

Název nakladatele

Astronomical Society of the Pacific

Místo vydání

San Francisco, USA

Místo konání akce

Praha

Datum konání akce

1. 1. 2016

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

000401591600011