High-mass Outflows Identified from COHRS CO (3–2) Survey

Abstract

An unbiased search of molecular outflows within the region of the CO High Resolution survey has identified 157 high-mass outflows from a sample of 770 APEX Telescope Large Area Survey of the Galaxy clumps with a detection rate of 20%. The detection rate of outflows increases for clumps with higher M clump , L bol , L bol / M clump , N H 2 , and T dust compared to the clumps with no outflow. The detection rates of the outflow increase from protostellar (8%) to young stellar object clump (17%) to massive star-forming clump (29%). The detection rate 26% for quiescent clump is preliminary, because the sample of quiescent clumps is small. A statistical relation between the outflow and clump masses for our sample is log ( M out / M ⊙ ) = ( − 1.1 ± 0.21 ) + ( 0.9 ± 0.07 ) log ( M clump / M ⊙ ) . The detection rate of outflows and the outflow mass-loss rate show an increase with increasing M clump , L bol , N H 2 , and T dust , which indicates that clumps with outflow with higher parameter values are at a more advanced evolutionary stage. The outflow mechanical force increases with increasing bolometric luminosities. No clear evidence has yet been found that higher-mass outflows have different launching conditions than low-mass outflows.