2025A&A...699A.369V

Context. The young massive cluster R136 at the center of 30 Doradus (30 Dor) in the Large Magellanic Cloud (LMC) generates a cavity in the surrounding molecular cloud. However, there is molecular gas between 2 and 10 pc in projection from R136's center. The region, known as the Stapler nebula, hosts the closest known molecular gas clouds to R136.
Aims. We investigated the properties of molecular gas in the Stapler nebula to better understand why these clouds survive so close in projection to R136.
Methods. We used Atacama Large Millimeter/Sub-millimeter Array 7m observations in Band 7 (345 GHz) of continuum emission, ¹²CO and ¹³CO, together with dense gas tracers CS, HCO⁺, and HCN. Our observations resolve the molecular clouds in the nebula into individual parsec-sized clumps. We determined the physical properties of the clumps using both dust and molecular emission, and compared the emission properties observed close to R136 to other clouds in the LMC.
Results. The densest clumps in our sample, where we observe CS, HCO⁺, and HCN, are concentrated in a northwest-southeast diagonal seen as a dark dust lane in HST images. Resolved clumps have masses between ∼200-2500 M_⊙, and the values obtained using the virial theorem are higher than the masses obtained through ¹²CO and ¹³CO luminosity. The velocity dispersion of the clumps is due both to self-gravity and to the external pressure of the gas. Clumps at the center of our map, which have detections of dense gas tracers (n_crit ∼ 10⁶ cm^–3 and above), are spatially coincident with young stellar objects.
Conclusions. The clumps' physical and chemical properties are consistent with other clumps in 30 Dor. We suggest that these clumps are the densest regions of a molecular cloud carved by the radiation of R136.