The structure of molecular gas associated with NGC 2264: wide-field 12CO and H2 imaging




We present wide-field, high-resolution imaging observations in 12CO 3 → 2 and H2 1–0 S(1) towards a ∼1 deg2 region of NGC 2264. We identify 46 H2 emission objects, of which 35 are new discoveries. We characterize several cores as protostellar, reducing the previously observed ratio of pre-stellar/protostellar cores in the NGC 2264 clusters. The length of H2 jets increases the previously reported spatial extent of the clusters. In each cluster, <0.5 per cent of cloud material has been perturbed by outflow activity. A principal component analysis of the 12CO data suggests that turbulence is driven on scales >2.6 pc, which is larger than the extent of the outflows. We obtain an exponent α= 0.74 for the size–linewidth relation, possibly due to the high surface density of NGC 2264. In this very active, mixed-mass star-forming region, our observations suggest that protostellar outflow activity is not injecting energy and momentum on a large enough scale to be the dominant source of turbulence.