2012ApJ...754...70S

Distribution of the CH₃ OH (J_K= 2_K-1_K, 96.7 GHz) emission has been investigated toward NGC 1333 IRAS4B, a low-mass Class 0 protostar which harbors a hot corino, with Nobeyama Millimeter Array. The CH₃ OH emission is found to be prominent in the shocked region caused by an impact of the molecular outflow from the protostars. The direction of the outflow which is responsible for the shock seems to be opposite to that of a compact outflow known previously in the CO (J = 2-1), HCN (J = 1-0), H₂ CO (3₁₂-2₁₁), and CH₃ OH (J_K= 7_K-6_K) emissions, whereas it is the same as that of the faint second outflow found in the H₂ CO emission. This double outflow structure can be interpreted most naturally by the existence of more than two protostars in IRAS4B. On the other hand, a centrally condensed component associated apparently with IRAS4B cannot be recognized in our CH₃ OH observation. Our observation suggests that, in this source, the CH₃ OH (J_K= 2_K-1_ K_) emission preferentially traces the shocked regions rather than the hot corino around the protostar.