ALMA Resolves 30 Doradus: Sub-parsec Molecular Cloud Structure Near the
  Closest Super-Star Cluster
  We present ALMA observations of 30 Doradus -- the highest resolution view of
molecular gas in an extragalactic star formation region to date (~0.4pc x
0.6pc). The 30Dor-10 cloud north of R136 was mapped in 12CO 2-1, 13CO 2-1, C18O
2-1, 1.3mm continuum, the H30alpha recombination line, and two H2CO 3-2
transitions. Most 12CO emission is associated with small filaments and clumps
(<1pc, ~1000 Msun at the current resolution). Some clumps are associated with
protostars, including "pillars of creation" photoablated by intense radiation
from R136. Emission from molecular clouds is often analyzed by decomposition
into approximately beam-sized clumps. Such clumps in 30 Doradus follow similar
trends in size, linewidth, and surface density to Milky Way clumps. The 30
Doradus clumps have somewhat larger linewidths for a given size than predicted
by Larson's scaling relation, consistent with pressure confinement. They extend
to higher surface density at a given size and linewidth compared to clouds
studied at 10pc resolution. These trends are also true of clumps in Galactic
infrared-dark clouds; higher resolution observations of both environments are
required. Consistency of clump masses calculated from dust continuum, CO, and
the virial theorem reveals that the CO abundance in 30 Doradus clumps is not
significantly different from the LMC mean, but the dust abundance may be
reduced by ~2. There are no strong trends in clump properties with distance
from R136; dense clumps are not strongly affected by the external radiation
field, but there is a modest trend towards lower dense clump filling fraction
deeper in the cloud.
