2018
Two-dimensional modeling of density and thermal structure of dense circumstellar outflowing disks
KURFÜRST, Petr, Achim FELDMEIER a Jiří KRTIČKAZákladní údaje
Originální název
Two-dimensional modeling of density and thermal structure of dense circumstellar outflowing disks
Autoři
KURFÜRST, Petr (203 Česká republika, garant, domácí), Achim FELDMEIER (276 Německo) a Jiří KRTIČKA (203 Česká republika, domácí)
Vydání
Astronomy and Astrophysics, Les Ulis, EDP Sciences, 2018, 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
Impakt faktor
Impact factor: 4.378 v roce 2014
Kód RIV
RIV/00216224:14310/18:00113946
Organizační jednotka
Přírodovědecká fakulta
UT WoS
000434420000001
Klíčová slova anglicky
stars: massive; stars: mass-loss; stars: winds-outflows; stars: evolution; stars: rotation; hydrodynamics
Štítky
Příznaky
Mezinárodní význam, Recenzováno
Změněno: 29. 4. 2021 11:07, Mgr. Marie Šípková, DiS.
Anotace
V originále
Context. Evolution of massive stars is affected by a significant loss of mass either via (nearly) spherically symmetric stellar winds or by aspherical mass-loss mechanisms, namely the outflowing equatorial disks. However, the scenario that leads to the formation of a disk or rings of gas and dust around massive stars is still under debate. Aims. We study the hydrodynamic and thermal structure of optically thick, dense parts of outflowing circumstellar disks that may be formed around various types of critically rotating massive stars, for example, Be stars, B[e] supergiant (sgB[e]) stars or Pop III stars. Methods. We specify the optical depth of the disk along the line-of-sight from stellar poles. Within the optically thick dense region we calculate the vertical disk thermal structure using the diffusion approximation while for the optically thin outer layers we assume a local thermodynamic equilibrium with the impinging stellar irradiation. We use two of our own types of hydrodynamic codes: two-dimensional operator-split numerical code and unsplit code based on the Roe's method. Results. Our models show the geometric distribution and contribution of viscous heating that begins to dominate in the central part of the disk. In the models of dense viscous disks the viscosity increases the central temperature up to several tens of thousands of Kelvins. The high mass-loss rates and high viscosity lead to instabilities with significant waves or bumps in density and temperature in the very inner disk region. Conclusions. The two-dimensional radial-vertical models of dense outflowing disks including the full Navier-Stokes viscosity terms show very high temperatures that are however limited to only the central disk cores inside the optically thick area, while near the edge of the optically thick region the temperature may be low enough for the existence of neutral hydrogen.
Návaznosti
GA16-01116S, projekt VaV |
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LM2010005, projekt VaV |
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