Two-dimensional modeling of density and thermal structure of
dense circumstellar outflowing disks

J 2018

Two-dimensional modeling of density and thermal structure of dense circumstellar outflowing disks

KURFÜRST, Petr, Achim FELDMEIER and Jiří KRTIČKA

Basic information

Original name

Two-dimensional modeling of density and thermal structure of dense circumstellar outflowing disks

Authors

KURFÜRST, Petr (203 Czech Republic, guarantor, belonging to the institution), Achim FELDMEIER (276 Germany) and Jiří KRTIČKA (203 Czech Republic, belonging to the institution)

Edition

Astronomy and Astrophysics, Les Ulis, EDP Sciences, 2018, 0004-6361

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10308 Astronomy

Country of publisher

France

Confidentiality degree

není předmětem státního či obchodního tajemství

References:

URL

Impact factor

Impact factor: 4.378 in 2014

RIV identification code

RIV/00216224:14310/18:00113946

Organization unit

Faculty of Science

DOI

http://dx.doi.org/10.1051/0004-6361/201731300

UT WoS

000434420000001

Keywords in English

stars: massive; stars: mass-loss; stars: winds-outflows; stars: evolution; stars: rotation; hydrodynamics

Abstract

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.

Links

GA16-01116S, research and development project

Name: Atmosféry a okolohvězdné prostředí magnetických horkých hvězd

Investor: Czech Science Foundation

LM2010005, research and development project

Name: Velká infrastruktura CESNET (Acronym: VI CESNET)

Investor: Ministry of Education, Youth and Sports of the CR

Citovat

KURFÜRST, Petr, Achim FELDMEIER and Jiří KRTIČKA. Two-dimensional modeling of density and thermal structure of dense circumstellar outflowing disks. Astronomy and Astrophysics. Les Ulis: EDP Sciences, 2018, vol. 613, May 2018, p. 1-24. ISSN 0004-6361. Available from: https://dx.doi.org/10.1051/0004-6361/201731300.

@article{1398835,
   author = {Kurfürst, Petr and Feldmeier, Achim and Krtička, Jiří},
   article_location = {Les Ulis},
   article_number = {May 2018},
   doi = {http://dx.doi.org/10.1051/0004-6361/201731300},
   keywords = {stars: massive; stars: mass-loss; stars: winds-outflows; stars: evolution; stars: rotation; hydrodynamics},
   language = {eng},
   issn = {0004-6361},
   journal = {Astronomy and Astrophysics},
   title = {Two-dimensional modeling of density and thermal structure of dense circumstellar outflowing disks},
   url = {http://adsabs.harvard.edu/abs/2017arXiv171202908K},
   volume = {613},
   year = {2018}
}

TY  - JOUR
ID  - 1398835
AU  - Kurfürst, Petr - Feldmeier, Achim - Krtička, Jiří
PY  - 2018
TI  - Two-dimensional modeling of density and thermal structure of dense circumstellar outflowing disks
JF  - Astronomy and Astrophysics
VL  - 613
IS  - May 2018
SP  - 1-24
EP  - 1-24
PB  - EDP Sciences
SN  - 00046361
KW  - stars: massive
KW  - stars: mass-loss
KW  - stars: winds-outflows
KW  - stars: evolution
KW  - stars: rotation
KW  - hydrodynamics
UR  - http://adsabs.harvard.edu/abs/2017arXiv171202908K
L2  - http://adsabs.harvard.edu/abs/2017arXiv171202908K
N2  - 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.
ER  -

KURFÜRST, Petr, Achim FELDMEIER and Jiří KRTIČKA. Two-dimensional modeling of density and thermal structure of dense circumstellar outflowing disks. \textit{Astronomy and Astrophysics}. Les Ulis: EDP Sciences, 2018, vol.~613, May 2018, p.~1-24. ISSN~0004-6361. Available from: https://dx.doi.org/10.1051/0004-6361/201731300.

Detailed Information on Publication Record