A mapping survey of massive CO cores

We mapped 21 star-forming regions with the 12CO, 13CO and C18O (1−0) lines using the 13.7-m telescope of Purple Mount Observatory. This mapping survey resolved 53 13CO cores, of which 22 are sourceless. We obtained the physical parameters of these cores. The relation between 13CO linewidth and core size and that between column density and core size were analysed. The cores 00211+6549−1 and 22566+5830 were found to have outflows. Systematic V LSR shifts were detected in nine regions: 00211+6549, 00232+6437, 05168+3634, 19199+1358, 20160+3911, 22566+5830, 23042+6000, S146 and S270. Signatures of infall and cloud collision were found in regions 18507+0121 and 19199+1358, respectively. We studied the mass function of these 13CO cores. The core masses range from 3.40 to 4.64 × 104M⊙, and the core mass function is a power-law distribution of index −0.82 ± 0.04.