A 257-273 GHz spectral survey of the OMC 1 cloud core.

A spectral line survey of the OMC1 cloud core has been obtained, over the frequency range 257.04-273.02 GHz, using the James Clerk Maxwell 15-m submillimeter telescope. Additional observations have been made centered at 229.4, 231.2, 237.3, and 239.1 GHz. A new algorithm was used to deconvolve the original double-sideband data, and its performance is critically discussed. One-hundred eighty-one distinct spectral lines were detected, about 7 of which are not identifiable with known molecular transitions. Between 18 and 21 molecular species were detected, including up to 10 isotopically-substituted forms. The line strengths are greater by a factor of 1.9 (on average) than in an earlier OVRO survey orf similar frequencies, made using a larger beam. The current results therefore provide a substantial data base of typical line strengths for future high-resolution studies of the OMC1 core.