Magnetically arrested disk flux eruption events to describe SgrA* flares

¹ Department of Physics, National and Kapodistrian University of Athens, University Campus, GR 15784 Zografos, Greece
² Research Center for Astronomy and Applied Mathematics, Academy of Athens, Soranou Efesiou 4, 115 27 Athens, Greece

^⋆ Corresponding author; elantonop@phys.uoa.gr

Received: 16 December 2024
Accepted: 5 February 2025

Abstract

Context. Magnetically arrested disks (MADs) are among the most suitable candidates for describing the gas accretion and observed emission in the vicinity of supermassive black holes.

Aims. We aim to establish a direct correlation between the quasiperiodic flux eruption events, characteristic of MAD accretion disk simulations, and the observed flaring behavior in the Galactic center.

Methods. We employed a MAD accretion disk with a distinct counterclockwise rotation and investigated the evolution of magnetized flux tubes generated during a prominent flux eruption event. Although these flux tubes have a clockwise pattern, they experience significant drag from the accretion disk’s rotation. We modeled the motion of hot spots, formed on the disk’s equatorial plane due to magnetic reconnection, as they travel along the magnetized flux tubes at a fraction of the speed of light.

Results. Hot spots with a relativistic ejection velocity are able to balance out the counterclockwise drag of the flux tube’s foot-point on the disk and move clockwise in the sky, which is in good agreement with the near-infrared flares in the Galactic center. In addition, our flare models favor face-on inclinations in the ranges [0° ,34° ] and [163° ,180° ] for SgrA*.

Conclusions. The flux eruption events that arise naturally in the MAD accretion state provide a promising framework for reproducing the observed flaring behavior in the vicinity of SgrA*.