Discovery of a dense molecular cloud towards a young massive embedded star in 30 Doradus

TL;DR

This paper reports the discovery of a dense molecular cloud near a young massive star in 30 Doradus, providing insights into star formation in low-metallicity environments of the Large Magellanic Cloud.

Contribution

The study presents the first detection and characterization of a dense molecular cloud associated with a young massive star in 30 Doradus, using high-sensitivity CO and CS line observations.

Findings

Discovered a dense molecular cloud near a young massive star in 30 Doradus.

Derived a molecular mass of less than 10^4 solar masses and a density greater than 10^3 cm^-3.

Detected CS emission indicating densities around 10^6 cm^-3.

Abstract

The 30 Doradus region in the Large Magellanic Cloud is one of the most outstanding star forming regions of the Local Group and a primary target to study star formation in an environment of low metallicity. In order to obtain a more complete picture of the not yet consumed or dispersed cool gas, we searched for line emission from molecular clouds that could be associated with molecular hydrogen emission detected in the region. We obtained a high sensitivity 12CO J=2-1 map with the 15-m SEST telescope, complemented by pointed observations of 13CO J=2-1 and CS J=2-1. We report the discovery of a dense molecular cloud towards an embedded young massive star at ~ 20" (~5 pc, at the distance of 50 kpc) northwest of R136, the compact massive central stellar cluster powering 30 Doradus in the LMC, that could be triggering star formation in the surrounding molecular clouds. We derived a molecular mass of $\lesssim 10^4$ \msol, a linear radius of 3 pc, as an upper limit, and a mean density of $\gtrsim 10^{3}$ cm$^{-3}$ for the cloud. The detection of CS J=2-1 emission line indicates larger densities, $\sim 10^{6}$ cm$^{-3}$. The dense molecular cloud is associated with molecular 2.12 um H2 emission. We suggest that the observed molecular gas could be the remains of dense molecular material surviving the action of strong UV fields and winds in which the young massive star has formed.