IONIZED CARBON IN THE LARGE MAGELLANIC CLOUD

We have observed the 158-mu-m 2P3/2-2P1/2 fine-structure transition of C+ at selected locations in the Large Magellanic Cloud. The C II emission is most intense toward far-infrared continuum peaks and generally is not seen in positions exhibiting strong CO J = 2-1 radiation. Where both C II and CO emission are detected, the V(LSR) centroids are similar but the C II line is wider. The differences in spatial distribution and spectral shape suggest a more pronounced physical separation between the predominantly neutral atomic and molecular gas regions than is the case in our Galaxy. In the LMC, the intense and extended C II emission near 30 Dor implies a total amount of C+ several times greater than that of Galactic molecular cloud complexes. We also attempted to detect the 289-mu-m J = 9-8 transition of (CO)-C-12 in a few locations. The observed upper intensity limit for N159 implies that moderate density (n > 4 x 10(4) cm-3) molecular gas fills less than 5% of our beam and that most of the low J CO emission comes from lower density gas.