Multipolar magnetic configuration: A trace of post-mergers events in circumstellar disks around FS CMa stars

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F47813059%3A19630%2F25%3AA0000457" target="_blank" >RIV/47813059:19630/25:A0000457 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216208:11320/25:10510252

Výsledek na webu

<a href="https://www.aanda.org/articles/aa/full_html/2025/11/aa53958-25/aa53958-25.html" target="_blank" >https://www.aanda.org/articles/aa/full_html/2025/11/aa53958-25/aa53958-25.html</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/0004-6361/202553958" target="_blank" >10.1051/0004-6361/202553958</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Multipolar magnetic configuration: A trace of post-mergers events in circumstellar disks around FS CMa stars

Popis výsledku v původním jazyce

Context. Observations suggest that the magnetic fields of disk-bearing stars can have non-dipolar configurations. However, the influence of these configurations on magnetospheric accretion remains poorly understood. Aims. We aim to simulate magnetospheric accretion by incorporating non-dipolar and strong magnetic field. Our model is informed by observations of IRAS 17449+2320, a post-merger belonging to the group of FS CMa stars, which indicate a dominant dipolar magnetic field with an additional quadrupole component. Methods. Using the PLUTO code, we conducted 2.5-D nonideal viscous-resistive (alpha(nu) = 1 and alpha(m )= 1) magnetohydrodynamic simulations of star-disk magnetospheric interactions. We considered a thin accretion disk and a strong stellar magnetic field (B-star = 6.2 kG) under four configurations: pure dipole, pure quadrupole, dipole plus quadrupole, and dipole plus octupole. In the latter two cases, different magnetic polar strength ratios were explored. Results. For asymmetric magnetic field configurations, we find that accretion exhibits funnel streams below the midplane, indicating the dominance of the quadrupolar and octupolar components. In contrast, in dipolar configurations, we observe the formation of two symmetrical funnels with respect to the midplane. However, in the quadrupolar configuration, accretion is entirely confined to the disk midplane forming a cone-like pattern that leads to disk widening. Remarkably, the presence of a quadrupolar component gives rise to highly asymmetric substructures in the corona region. Conclusions. Multipolar stellar magnetic fields drive nonuniform accretion and lead to asymmetric density distributions in both the disk and corona. These results resemble observed features of some FS CMa post-mergers and Herbig Ae/Be stars, highlighting the critical role of magnetic field complexity in shaping circumstellar environments.

Název v anglickém jazyce

Multipolar magnetic configuration: A trace of post-mergers events in circumstellar disks around FS CMa stars

Popis výsledku anglicky

Context. Observations suggest that the magnetic fields of disk-bearing stars can have non-dipolar configurations. However, the influence of these configurations on magnetospheric accretion remains poorly understood. Aims. We aim to simulate magnetospheric accretion by incorporating non-dipolar and strong magnetic field. Our model is informed by observations of IRAS 17449+2320, a post-merger belonging to the group of FS CMa stars, which indicate a dominant dipolar magnetic field with an additional quadrupole component. Methods. Using the PLUTO code, we conducted 2.5-D nonideal viscous-resistive (alpha(nu) = 1 and alpha(m )= 1) magnetohydrodynamic simulations of star-disk magnetospheric interactions. We considered a thin accretion disk and a strong stellar magnetic field (B-star = 6.2 kG) under four configurations: pure dipole, pure quadrupole, dipole plus quadrupole, and dipole plus octupole. In the latter two cases, different magnetic polar strength ratios were explored. Results. For asymmetric magnetic field configurations, we find that accretion exhibits funnel streams below the midplane, indicating the dominance of the quadrupolar and octupolar components. In contrast, in dipolar configurations, we observe the formation of two symmetrical funnels with respect to the midplane. However, in the quadrupolar configuration, accretion is entirely confined to the disk midplane forming a cone-like pattern that leads to disk widening. Remarkably, the presence of a quadrupolar component gives rise to highly asymmetric substructures in the corona region. Conclusions. Multipolar stellar magnetic fields drive nonuniform accretion and lead to asymmetric density distributions in both the disk and corona. These results resemble observed features of some FS CMa post-mergers and Herbig Ae/Be stars, highlighting the critical role of magnetic field complexity in shaping circumstellar environments.

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)<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2025

Kód důvěrnosti údajů

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

Název periodika

ASTRONOMY &amp; ASTROPHYSICS

ISSN

0004-6361

e-ISSN

—

Svazek periodika

703

Číslo periodika v rámci svazku

October 25

Stát vydavatele periodika

FR - Francouzská republika

Počet stran výsledku

11

Strana od-do

„703-1“-„703-11“

Kód UT WoS článku

001606951900010

EID výsledku v databázi Scopus

2-s2.0-105021109243