MOLECULAR ABUNDANCES IN THE MAGELLANIC CLOUDS .2. DEUTERATED SPECIES IN THE LMC

The first definite discoveries of extragalactic deuterium are reported . DCO+ has been detected in three and DCN has been measured in one sta r-forming region of the Large Magellanic Cloud (LMC). While the HCO+/D CO+ abundance ratios are found to be 19 +/- 3, 24 +/- 4, and 67 +/- 18 for N113, N44BC and N159HW, respectively, a HCN/DCN abundance ratio o f 23 +/- 5 is obtained for N113. These results are consistent with a g as temperature of about 20 K and a D/H ratio of about 1.5 x 10(-5), co nsistent with that observed in the Galaxy. If the cloud temperature is closer to 30 K, then a D/H ratio is required to be up to an order of magnitude larger. Because this ratio provides a lower limit to the pri mordial D/H ratio, it indicates that the baryon mass density alone is unable to close the universe.