Abstract
We have conducted a sensitive 3mm observation toward the shocked region, Lynds 1157 B1, which is an interaction spot between a molecular outflow and its ambient gas. We have successfully detected the CH 3 CHO, HCOOCH 3 , and HCOOH lines, as well as the CH 2 DOH line. The abundances of these molecules relative to CH 3 OH are found to be lower than those in the low-mass star-forming core, IRAS 16293-2422. Since these molecules are thought to evaporate from grain mantles, the observational results mean that complex molecules are less abundant in grain mantles residing in the ambient cloud surrounding a prestellar/protostellar core. Instead, efficient formation of the complex organic species and deuterated species should take place in a prestellar/protostellar core. The present result verifies the importance of an unbiased line survey of this source. © 2011. Astronomical Society of Japan.