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

Kód výsledku v 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>

Výsledek na webu

<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>

Jazyk výsledku

angličtina

Název v původním jazyce

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

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

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

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

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

Rok uplatnění

2024

Kód důvěrnosti údajů

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

Název periodika

Monthly Notices of the Royal Astronomical Society

ISSN

0035-8711

e-ISSN

1365-2966

Svazek periodika

528

Číslo periodika v rámci svazku

4

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

10

Strana od-do

7310-7319

Kód UT WoS článku

001177674300019

EID výsledku v databázi Scopus

2-s2.0-85186264277