2.5-MHD models of circumstellar discs around FS CMa post-mergers: II. Stationary accretion stage

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F24%3A10492996" target="_blank" >RIV/00216208:11320/24:10492996 - isvavai.cz</a>

Result on the web

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=R7sxsjVzEp" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=R7sxsjVzEp</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1093/mnras/stae324" target="_blank" >10.1093/mnras/stae324</a>

Result language

angličtina

Original language name

2.5-MHD models of circumstellar discs around FS CMa post-mergers: II. Stationary accretion stage

Original language description

We study the star-disc interaction in the presence of the strong magnetic field (B-star = 6.2 kG) of a slowly rotating star. This situation describes a post-merger of the spectral type B and has not been previously investigated. We perform a set of resistive and viscosity 2.5D-magnetohydrodynamical simulations using the PLUTO code. Based on our previous work, we consider the initial gas disc density rho(d0) = 10(-13) g cm(-3) since it describes the conditions around IRAS 17449+2320 well. We find that the fall of gas towards the star occurs in the mid-plane, and remarkably, intermittent backflow takes place in the mid-plane in all of our models for R &gt;= 10R(star). However, we do not rule out that the funnel effect may occur and cause the accretion closer to the poles. Also, when larger values of viscosity (alpha(nu) = 1) and stellar rotation rate (delta(star) = 0.2) are considered, we find that the disc exhibits a thickening which is characteristic of FS CMa-type stellar objects. Additionally, we find that the poloidal magnetic field lines twist over short periods of time, leading to magnetic reconnection causing coronal heating that could explain the presence of the Raman lines found observationally in several FS CMa stars. Lastly, we find the formation of several knots in the magnetic field lines near and in the mid-plane of the disc which produce perturbations in the density and velocity components, as well as the formation of shallow gaps whose position depends on the inflation of the magnetic field lines.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

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

Publication year

2024

Confidentiality

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

Name of the periodical

Monthly Notices of the Royal Astronomical Society

ISSN

0035-8711

e-ISSN

1365-2966

Volume of the periodical

528

Issue of the periodical within the volume

4

Country of publishing house

GB - UNITED KINGDOM

Number of pages

10

Pages from-to

7310-7319

UT code for WoS article

001177674300019

EID of the result in the Scopus database

2-s2.0-85186264277