Early stage massive star formation near the Galactic Center: Sgr C

TL;DR

This study provides detailed observations of early-stage massive star formation near Sgr C in the Galactic Center, identifying protostellar cores and analyzing the physical conditions of the host molecular cloud.

Contribution

It offers new observational evidence of early massive star formation at the periphery of the Sgr C HII region and characterizes the physical properties of the associated molecular cloud.

Findings

Detection of two protostellar cores with ~10^3 Msun mass

Identification of an Extended Green Object indicating embedded protostar activity

Host cloud contains ~10^5 Msun of gas, suitable for star formation

Abstract

We present near-infrared spectroscopy and 1 mm line and continuum observations of a recently identified site of high mass star formation likely to be located in the Central Molecular Zone near Sgr C. Located on the outskirts of the massive evolved HII region associated with Sgr C, the area is characterized by an Extended Green Object measuring ~10" in size (0.4 pc), whose observational characteristics suggest the presence of an embedded massive protostar driving an outflow. Our data confirm that early-stage star formation is taking place on the periphery of the Sgr C HII region, with detections of two protostellar cores and several knots of H2 and Brackett gamma emission alongside a previously detected compact radio source. We calculate the cores' joint mass to be ~10^3 Msun, with column densities of 1-2 x 10^24 cm-2. We show the host molecular cloud to hold ~10^5 Msun of gas and dust with temperatures and column densities favourable for massive star formation to occur, however, there is no evidence of star formation outside of the EGO, indicating that the cloud is predominantly quiescent. Given its mass, density, and temperature, the cloud is comparable to other remarkable non-star-forming clouds such as G0.253 in the Eastern CMZ.