THE 685-692 GHZ SPECTRUM OF THE ORION CORE

We used the new Max Planck Institute for Extraterrestrial Physics submillimeter spectrometer to measure the 685-692 GHz (438-434 mu m) spectrum of the Orion core in the James Clerk Maxwell Telescope's 7 '' beam. We detected 13 lines from the ''Compact Ridge'' and ''Plateau'' outflow over this 7 GHz wide band. Our map of the (HCN)-C-13 J = 8-7 line shows that the densest part of the outflow is more compact (4 '' FWHM) than the SO-emitting region (similar to 12 ''). Observation of both (HCN)-C-13 and (HCN)-N-15 J = 8-7 lines indicates 200 K, 10(9) cm(-3) gas either with an H-2 column density of similar to 2 x 10(24) cm(-2) or With modestly enhanced HCN abundances in the warm and dense core of the outflow. Although the true continuum level is clearly present between the lines, the lines are still strong and contribute up to 50% of the total flux in this relatively crowded part of the spectrum.