title: Origin of the Chemical Diversity in Low-Mass Star Forming Regions

authors: Nami Sakai and Satoshi Yamamoto

abstract: Low-mass protostellar cores in the Class 0 stage were found to harbor various complex organic molecules (COMs) in the vicinity of the protostar.  However, they reveal significant chemical diversity among the sources.  We now know at least two distinct families in chemical composition.  One is a hot corino characterized by saturated COMs such as (CH3)2O and C2H5CN.  The other is a warm-carbon-chain chemistry (WCCC) source characterized by unsaturated COMs (carbon-chain molecules and their related molecules). The striking chemical difference is clearly demonstrated by exclusive chemical composition revealed by the spectral line surveys and the ALMA observations for IRAS16293-2422 (hot corino) and L1527 (WCCC).  In WCCC, CH4 evaporated from grain mantle near the protostar triggers efficient production of various carbon-chain molecules.  On the other hand, saturated COMs are thought to be formed on grain mantles and are evaporated in the vicinity of the protostar.  Thus, the difference would originate from the ice composition of the grain mantle.  In this poster, we will discuss how the different ice compositions can be formed in relation to environments of their parent clouds.