Speaker
Description
We analyze the line ratio of the 13CO(2–1) to 12CO(2–1) rotational transitions observed from new Atacama Large Millimeter/submillimeter Array observations of 100 Giant Molecular Clouds that span the Large Magellanic Cloud. We measure a median line ratio of 13CO(2–1)/12CO(2–1) = 0.078 with 68% of the sample falling between 0.058 and 0.107. A regression analysis confirms a nearly linear relationship across two orders of magnitude in line luminosity. Moreover, we find that the inclusion of (LFIR) from Young Stellar Objects (YSOs) as a predictor variable of the line ratio significantly improves the quality of the fit, with clouds hosting IR-bright YSOs having relatively brighter 13CO emission. This analysis indicates that active star-forming molecular clouds have different internal conditions than more quiescent clouds.