Magnetically arrested disk flux eruption events to describe SgrA* flares

TL;DR

This study links magnetically arrested disk flux eruption events to the flaring activity observed near SgrA*, modeling hot spot dynamics and matching observed near-infrared flares with specific inclination angles.

Contribution

It introduces a model connecting flux eruption events in MAD disks to SgrA* flares, emphasizing hot spot motion and inclination constraints.

Findings

Hot spots can produce relativistic ejections matching observed flares.

Flux eruption events naturally explain SgrA*'s flaring behavior.

Preferred face-on inclination angles are identified for SgrA*.

Abstract

Context. Magnetically arrested disks are among the most suitable candidates for describing the gas accretion and observed emission in the vicinity of supermassive black holes. Aims. This work aims to provide a direct correlation between the quasi-periodic flux eruption events, characteristic of MAD accretion disk simulations, and the observed flaring behavior in the Galactic center. Methods. We employ a MAD accretion disk with a distinct counter-clockwise rotation and investigate the evolution of magnetized flux tubes generated during a prominent flux eruption event. Although these flux tubes demonstrate a clockwise pattern, they experience significant dragging by the accretion disk's rotation. This study models 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 counter-clockwise dragging of the flux tube's foot-point on the disk and demonstrate a clockwise motion in the sky, that is in good agreement with the NIR flares in the Galactic center. In addition, our flare models favor face-on inclinations in the range $[0^\circ, 34^\circ]$ and $[163^\circ, 180^\circ]$ 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*.