From Gas to Stars in Energetic Environments: Dense Gas Clumps in the 30 Doradus Region Within the Large Magellanic Cloud

TL;DR

This study uses high-resolution interferometric maps to analyze dense gas clumps in the 30 Doradus star-forming region, revealing filamentary structures, gravitational collapse, and correlations with star formation indicators in a low-metallicity, high-radiation environment.

Contribution

First detailed interferometric analysis of dense gas in 30 Doradus, showing filamentary structures and star formation activity in an extreme environment.

Findings

13 dense clumps detected within 30 Doradus-10

Filamentary structure consistent with fluid instability formation

Clumps are gravitationally unstable and collapsing to form stars

Abstract

We present parsec scale interferometric maps of HCN(1-0) and HCO$^{+}$(1-0) emission from dense gas in the star-forming region 30 Doradus, obtained using the Australia Telescope Compact Array. This extreme star-forming region, located in the Large Magellanic Cloud (LMC), is characterized by a very intense ultraviolet ionizing radiation field and sub-solar metallicity, both of which are expected to impact molecular cloud structure. We detect 13 bright, dense clumps within the 30 Doradus-10 giant molecular cloud. Some of the clumps are aligned along a filamentary structure with a characteristic spacing that is consistent with formation via the varicose fluid instability. Our analysis shows that the filament is gravitationally unstable and collapsing to form stars. There is a good correlation between HCO$^{+}$ emission in the filament and signatures of recent star formation activity including H$_{2}$O masers and young stellar objects (YSOs). YSOs seem to continue along the same direction of the filament toward the massive compact star cluster R136 in the southwest. We present detailed comparisons of clump properities (masses, linewidths, sizes) in 30Dor-10 to those in other star forming regions of the LMC (N159, N113, N105, N44). Our analysis shows that the 30Dor-10 clumps have similar mass but wider linewidths and similar HCN/HCO$^{+}$ (1-0) line ratios as clumps detected in other LMC star-forming regions. Our results suggest that the dense molecular gas clumps in the interior of 30Dor-10 are well-shielded against the intense ionizing field that is present in the 30Doradus region.