Chemical Differentiation around Five Massive Protostars Revealed by ALMA: Carbon-chain Species and Oxygen/Nitrogen-bearing Complex Organic Molecules

Abstract We present Atacama Large Millimeter/submillimeter Array Band 3 data toward five massive young stellar objects (MYSOs), and investigate relationships between unsaturated carbon-chain species saturated complex organic molecules (COMs). An HC 5 N ( J = 35–34) line has been detected from three MYSOs, where nitrogen (N)-bearing COMs (CH 2 CHCN CH CN) have detected. The spatial distributions show compact features match with a methanol OH) an upper-state energy around 300 K, which should trace hot cores. regions are more extended the MYSOs N-bearing compared to two without these molecular lines, while there no clear differences in bolometric luminosity temperature. run chemical simulations of hot-core models warm-up stage, compare observational results. observed abundances good agreements model at stage temperatures above 160 K. These results indicate that chemistry cannot be reproduced by warm chemistry, new type occurs MYSOs.