Milky Way Supermassive Black Hole: Dynamical Feeding from the Circumnuclear Environment

TL;DR

This study reveals that the circumnuclear disk around the Milky Way's supermassive black hole is dynamically evolving, with large-scale gas streamers feeding the central region, indicating episodic accretion processes.

Contribution

It provides new observational evidence of large-scale molecular arms connecting to the circumnuclear disk, highlighting its dynamic and non-stationary nature.

Findings

Identification of >5-10 pc scale molecular arms connecting to the CND

Evidence of gas inflow via streamers towards the SMBH

CND is a dynamic structure, not a steady state

Abstract

The supermassive black hole (SMBH), Sgr A*, at the Galactic Center is surrounded by a molecular circumnuclear disk (CND) lying between 1.5-4 pc radii. The irregular and clumpy structures of the CND, suggest dynamical evolution and episodic feeding of gas towards the central SMBH. New sensitive data from the SMA and GBT, reveal several >5-10 pc scale molecular arms, which either directly connect to the CND, or may penetrate inside the CND. The CND appears to be the convergence of the innermost parts of largescale gas streamers, which are responding to the central gravitational potential well. Rather than being a quasi-stationary structure, the CND may be dynamically evolving, incorporating inflow via streamers, and feeding gas towards the center.