An out-of-plane galactic carbon monoxide survey

Abstract

Galactic CO line emission at 115 GHz has been surveyed in the region from 15 to 60 deg galactic longitude and from about -1.5 to 1.5 deg latitude. In addition to confirming the findings of previous in-plane surveys that galactic CO emission is concentrated in a ring 6 kpc in radius, a fit of a cylindrically symmetric galactic model to the observational data has provided a determination of the thickness of this molecular ring and its displacement from the conventional galactic plane, both as functions of galactocentric distance. The average half-thickness at half-maximum of the molecular ring is 59 pc, and the average displacement of the ring with respect to the galactic equatorial plane is -40 pc.