Observations of CO J = 3 → 2 emission from molecular clouds

Observational studies of interstellar Carbon Monoxide have enabled astronomers to gather a wealth of information on the structure, energetics and kinematics of galactic molecular clouds. In this paper new data obtained using the 3.8 m United Kingdom Infrared Telescope (UKIRT) with the QMC and UKIRT submillimeter heterodyne receivers are reported. These cryogenic heterodyne systems have system noise temperatures varying between 270 K at 220 GHz and 400 K at 370 GHz. Spectra and maps have been obtained towards many galactic star formation regions (NGC 1333 (IRS-1), NGC 2071, Mon R2 and AFGL 961). Some of the observed data in the J = 1 → 0, J = 2 → 1 and J = 3 → 2 CO transitions, where the data from lower transitions are collected from the literature using telescopes with similar beam sizes, are compared. (Auth.)