The molecular cloud population of the large magellanic cloud

We have mapped an extensive sample of molecular clouds in the Large Magellanic Cloud (LMC) at 11 pc resolution in the CO(1-0) line as part of the Magellanic Mopra Assessment (MAGMA). We identify clouds as regions of connected CO emission and determine their sizes, line widths, and fluxes. We find that GMCs are not preferentially located in regions of high Hi line width or velocity gradient, and that there is no clear Hi column density threshold for CO detection. The luminosity function of CO clouds is steeper than dN/dL ∞ L ^-2, suggesting a substantial fraction of mass in low-mass clouds. The correlation between size and linewidth, while apparent for the largest emission structures, breaks down when those structures are decomposed into smaller structures. The virial parameter (the ratio of a cloud's kinetic to gravitational energy) shows a wide range of values and exhibits no clear trends with the likelihood of hosting young stellar object (YSO) candidates, suggesting that this parameter is a poor reflection of the evolutionary state of a cloud. More massive GMCs are more likely to harbor a YSO candidate, and more luminous YSOs are more likely to be coincident with detectable CO emission, confirming GMCs as the principal sites of massive star formation.