Molecular and ionized gas kinematics in the GC Radio Arc

TL;DR

This study uses radio observations to analyze the gas dynamics in the Galactic Center's Radio Arc, revealing physical connections between molecular clouds, an expanding shell near the Quintuplet cluster, and dense gas with no current star formation.

Contribution

It provides new insights into the gas kinematics and physical connections of molecular clouds in the Radio Arc region using high-resolution radio observations.

Findings

Connected velocity components in M0.20-0.033 suggest an expanding shell.

G0.10-0.08 has dense molecular gas with no signs of star formation.

Detection of CH3OH masers indicates dense gas conditions.

Abstract

We present NH3 and H64a+H63a VLA observations of the Radio Arc region, including the M0.20-0.033 and G0.10-0.08 molecular clouds. These observations suggest the two velocity components of M0.20-0.033 are physically connected in the south. Additional ATCA observations suggest this connection is due to an expanding shell in the molecular gas, with the centroid located near the Quintuplet cluster. The G0.10-0.08 molecular cloud has little radio continuum, strong molecular emission, and abundant CH3OH masers, similar to a nearby molecular cloud with no star formation: M0.25+0.01. These features detected in G0.10-0.08 suggest dense molecular gas with no signs of current star formation.