Published online by Cambridge University Press: 14 August 2015
The upper half of the frequency band lying between the atmospheric water lines at 183 and 323 GHz is virtually unexplored by spectroscopists of interstellar matter. The only published observations are those of Huggins et al. (1979) who detected the J=3-2 lines of HCN, HNC, and HCO+ in the Orion A molecular cloud (OMC-1). We report here the results of extensive observations made in March and April of 1979 with a University of California (Berkeley) receiver on the Texas 4.9-m antenna.