ATCA 1.2 cm Observations of the Massive Star Forming Region G305.2+0.2

TL;DR

This study uses 1.2 cm observations to analyze the hot core G305.2+0.2, revealing molecular emissions, temperature estimates, chemical modeling, and maser activity, providing insights into its evolutionary stage.

Contribution

It presents new observational data and chemical modeling of G305.2+0.2, including temperature estimates and maser detections, advancing understanding of massive star formation regions.

Findings

Detected molecular emissions confirming hot core nature.

Estimated gas temperature around 200 K.

Identified potential Class I methanol maser activity.

Abstract

We report on Australia Telescope observations of the massive star forming region G305.2+0.2 at 1.2 cm. We detected emission in five molecules towards G305A, confirming its hot core nature. We determined a rotational temperature of 26 K for methanol. A non-LTE excitation calculation suggests a kinematic temperature of order 200 K. A time dependent chemical model is also used to model the gas phase chemistry of the hot core associated with G305A. A comparison with the observations suggest an age of between 2 x10^4 and 1.5 x10^5 years. We also report on a feature to the SE of G305A which may show weak Class I methanol maser emission in the line at 24.933 GHz. The more evolved source G305B does not show emission in any of the line tracers, but strong Class I methanol maser emission at 24.933 GHz is found 3\arcsec to the east. Radio continuum emission at 18.496 GHz is detected towards two \hii regions. The implications of the non-detection of radio continuum emission toward G305A and G305B are also discussed.