A 13 CO and C 18 O Survey of the Molecular Gas Around Young Stellar Clusters within 1 Kiloparsec of the Sun

Abstract

As the first step of a multiwavelength investigation into the relationship between young stellar clusters and their environment, we present fully sampled maps in the J=1-0 lines of 13CO and C18O and the J=2-1 line of C18O for a selected group of 30 young stellar groups and clusters within 1 kpc of the Sun. This is the first systematic survey of these regions to date. The clusters range in size from several stars to a few hundred stars. Thirty fields ranging in size from 8'×8' to 30'×60' were mapped with 47" resolution simultaneously in the two J=1-0 lines at the Five College Radio Astronomy Observatory. Seventeen sources were mapped over fields ranging in size from 3'×3' to 13'×13' in the J=2-1 line with 35" resolution at the Submillimeter Telescope Observatory. We compare the cloud properties derived from each of the three tracers in order to better understand systematic uncertainties in determining masses and line widths. Cloud masses are determined independently using the 13CO and C18O transitions; these masses range from 30 to 4000 Msolar. Finally, we present a simple morphological classification scheme, which may serve as a rough indicator of cloud evolution.