Mass flows in the Galactic Center by supernovae of the circumnuclear disk

TL;DR

This study uses MHD simulations to investigate how supernova explosions near the Galactic Center's circumnuclear disk temporarily increase mass inflow to the SMBH and influence the disk's dynamics over hundreds of thousands of years.

Contribution

It provides the first detailed simulation-based analysis of supernova impacts on mass flows and turbulence in the Galactic Center's circumnuclear disk.

Findings

Supernovae cause a temporary increase of 2-60 M$_\ ext{\odot}$ in accretion rate.

Explosions can eject about 100 M$_\ ext{\odot}$ of warm gas from the CND.

Effects on mass flow and turbulence dissipate after approximately 250 kyr.

Abstract

Context. The circumnuclear disk (CND) is presently the main supply of mass for the accretion onto the supermassive black hole (SMBH) in the Galactic Center (GC). While the accretion is relatively slow, it has been suspected that local episodic explosive events play an important role in the temporary mass inflow toward the SMBH, while also affecting the evolution of the CND. Aims. The aim of this study is to follow the changes in mass flows caused by supernova (SN) explosions nestled in or near the CND. Methods. We perform simulations with the grid-based MHD code FLASH of the inner 5 pc of the Milky Way GC, including gravitational potential, rotation, magnetic field, central wind source, and the warm gas of the CND, all mimicking the observed physical properties. Results. Assuming a M$_\mathrm{SN}=10$ M$_\odot$ as the mass of the precursor of the core-collapse SN event at various locations within 2 pc from the GC, we detect a temporary increase in the accretion rate, transferring an additional 2-60 M$_\odot$ of warm gas to the immediate vicinity of the SMBH, depending on the explosion site. At the same time, the kinetic energy of the SN blows away even mass from the CND; the additional warm gas leaving the simulation domain after the explosion is on the order of $\sim100$ M$_\odot$. In the studied cases, the impact on mass flows and the turbulence caused by the explosion cease after $\sim250$ kyr.