Tidally-disrupted Molecular Clouds falling to the Galactic Center

TL;DR

This study identifies a molecular cloud connecting the outer galaxy to the Galactic Center Mini-spiral, showing signs of tidal disruption and ionization, providing insights into gas inflow processes near Sgr A*.

Contribution

It presents the first detailed observation of a molecular cloud actively falling into the Galactic Center, linking molecular and ionized gas streams.

Findings

Molecular cloud connected to the GCMS in morphology and velocity.

Evidence of tidal disruption and ionization near Sgr A*.

Detection of shocked gas at the boundary area.

Abstract

We found a molecular cloud connecting from the outer region to the "Galactic Center Mini-spiral (GCMS)" which is a bundle of the ionized gas streams adjacent to Sgr A*. The molecular cloud has a filamentary appearance which is prominent in the CS J=2-1 emission line and is continuously connected with the GCMS. The velocity of the molecular cloud is also continuously connected with that of the ionized gas in the GCMS observed in the H42alpha recombination line. The morphological and kinematic relations suggest that the molecular cloud is falling from the outer region to the vicinity of Sgr A*, being disrupted by the tidal shear of Sgr A* and ionized by UV emission from the Central Cluster. We also found the SiO J=2-1 emission in the boundary area between the filamentary molecular cloud and the GCMS. There seems to exist shocked gas in the boundary area.