J 2023

Accretion disc backflow in resistive MHD simulations

MISHRA, R., Miljenko ČEMELJIĆ and Wlodzimierz KLUŹNIAK

Basic information

Original name

Accretion disc backflow in resistive MHD simulations

Authors

MISHRA, R., Miljenko ČEMELJIĆ (191 Croatia, belonging to the institution) and Wlodzimierz KLUŹNIAK (616 Poland)

Edition

Monthly Notices of the Royal Astronomical Society, 2023, 0035-8711

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10308 Astronomy

Country of publisher

United Kingdom of Great Britain and Northern Ireland

Confidentiality degree

není předmětem státního či obchodního tajemství

References:

RIV identification code

RIV/47813059:19630/23:A0000262

Organization unit

Institute of physics in Opava

UT WoS

001019516400005

Keywords in English

accretion; accretion discs;magnetic fields;(magnetohydrodynamics) MHD;methods: numerical

Tags

Tags

International impact, Reviewed

Links

GX21-06825X, research and development project.
Změněno: 14/2/2024 11:18, Mgr. Pavlína Jalůvková

Abstract

V originále

We investigate accretion onto a central star, with the size, rotation rate, and magnetic dipole of a young stellar object, to study the flow pattern (velocity and density) of the fluid within and outside of the disc. We perform resistive magnetohydrodynamic (MHD) simulations of thin discs, varying the parameters such as the stellar rotation rate and (anomalous) coefficients of viscosity and resistivity in the disc. To provide a benchmark for the results and to compare them with known analytic results, we also perform purely hydrodynamic (HD) simulations for the same problem. Although obtained for different situations with differing inner boundary condition, the disc structure in the HD simulations closely follows the analytic solution of Kluzniak and Kita - in particular, a region of 'mid-plane' backflow exists in the right range of radii, depending on the viscosity parameter. In the MHD solutions, whenever the magnetic Prandtl number does not exceed a certain critical value, the mid-plane backflow exists throughout the accretion disc, extending all the way down to the foot point of the accretion funnel flow where the disc transitions to a magnetic funnel flow. For values of the magnetic Prandtl number close to the critical value the backflow and the inner disc undergo a quasi-periodic radial oscillation, otherwise the backflow is steady, as is the disc solution. From our results, supplemented by our reading of the literature, we suggest that mid-plane backflow is a real, physical, and not only numerical feature of at least some accretion discs.