2023
Accretion disc backflow in resistive MHD simulations
MISHRA, R., Miljenko ČEMELJIĆ a Wlodzimierz KLUŹNIAKZákladní údaje
Originální název
Accretion disc backflow in resistive MHD simulations
Autoři
MISHRA, R., Miljenko ČEMELJIĆ (191 Chorvatsko, domácí) a Wlodzimierz KLUŹNIAK (616 Polsko)
Vydání
Monthly Notices of the Royal Astronomical Society, 2023, 0035-8711
Další údaje
Jazyk
angličtina
Typ výsledku
Článek v odborném periodiku
Obor
10308 Astronomy
Stát vydavatele
Velká Británie a Severní Irsko
Utajení
není předmětem státního či obchodního tajemství
Odkazy
Kód RIV
RIV/47813059:19630/23:A0000262
Organizační jednotka
Fyzikální ústav v Opavě
UT WoS
001019516400005
Klíčová slova anglicky
accretion; accretion discs;magnetic fields;(magnetohydrodynamics) MHD;methods: numerical
Příznaky
Mezinárodní význam, Recenzováno
Návaznosti
GX21-06825X, projekt VaV.
Změněno: 14. 2. 2024 11:18, Mgr. Pavlína Jalůvková
Anotace
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.