Title: ALMA Reveals Internal Structure of Molecular Clouds in the LMC at Various Evolutionary 
Stages

Abstract:
We carried out high-resolution (0.7 pc) 12CO J=1-0 mosaic observations of five giant molecular 
clouds (GMCs) in the Large Magellanic Cloud with ALMA.  The five sample GMCs cover a wide 
range of evolutionary stages based on their associations to recent massive star formation 
(Types I to III; Kawamura et al. 2009).  Preliminary results from the data delivered so far are 
presented.  We adopt the brightness distribution function (BDF; the histogram of the line 
brightness) and the brightness distribution index (BDI; the luminosity ratio between bright and 
faint emission) to quantify the variety of state and structure of the gas.  A few GMCs possess 
bright compact structures, which are represented by long-tailed BDFs and high BDIs.  These 
characteristics resemble the gas in the spiral arms of the Milky Way (MW) observed at a 
similar spatial resolution (Sawada et al. 2012a), possibly indicating the readiness for star 
formation in these GMCs (Sawada et al. 2012b).  The other GMCs (Type I) are less structured, 
similar to the inter-arm gas in the MW.  The data imply that the internal structure develops as a 
cloud evolves.