A STUDY OF THE RELATION BETWEEN STAR FORMATION AND MOLECULAR CLUMPS ON SUBPARSEC SCALES IN 30 DORADUS

Abstract

ABSTRACT We present 12CO and 13CO molecular gas data observed by ALMA, massive early-stage young stellar objects (YSOs) identified by applying color–magnitude cuts to Spitzer and Herschel photometry, and low-mass late-stage YSOs identified via excess. Using dendrograms, we derive properties for the molecular cloud structures. This is the first time a dendrogram analysis has been applied to extragalactic clouds. The majority of clumps have a virial parameter equal to unity or less. The size–linewidth relations of 12CO and 13CO show the clumps in this study have a larger linewidth for a given size (by factors of 3.8 and 2.5, respectively) in comparison to several, but not all, previous studies. The larger linewidths in 30 Doradus compared to typical Milky Way quiescent clumps are probably due to the former’s highly energetic environmental conditions. The slopes of the size–linewidth relations of 12CO, 0.65 ± 0.04, and 13CO, 0.97 ± 0.12, are on the higher end but consistent within 3σ of those of previous studies. Massive star formation occurs in clumps with high masses (>1.83 × 102 M ⊙), high linewidths (v > 1.18 km s−1), and high mass densities (>6.67 × 102 M ⊙ pc−2). The majority of embedded, massive YSOs are associated with a clump; however, the majority of more evolved, low-mass YSOs are not.