Carbon-Chain Chemistry vs. Complex-Organic-Molecule Chemistry in Envelopes around Three Low-Mass Young Stellar Objects in the Perseus Region

We have analyzed ALMA Cycle 5 data in Band 4 toward three low-mass young stellar objects (YSOs), 18 IRAS 03235+3004 (hereafter IRAS 03235), IRAS 03245+3002 (IRAS 03245), and IRAS 03271+3013 19 (IRAS 03271), in the Perseus region. The HC3N (J = 16􀀀15; Eup=k = 59:4 K) line has been detected 20 in all of the target sources, while four CH3OH lines (Eup=k = 15:4􀀀36:3 K) have been detected 21 only in IRAS 03245. Sizes of the HC3N distributions ( 2930􀀀3230 au) in IRAS 03235 and IRAS 22 03245 are similar to those of the carbon-chain species in the warm carbon chain chemistry (WCCC) 23 source L1527. The size of the CH3OH emission in IRAS 03245 is 1760 au, which is 24 slightly smaller than that of HC3N in this source.We compare the CH3OH/HC3N abundance 25 ratios observed in these sources with predictions of chemical models. We conrm that the observed 26 ratio in IRAS 03245 agrees with the modeled values at temperatures around 30{35 K, which supports 27 the HC3N formation by the WCCC mechanism. In this temperature range, CH3OH does not thermally 28 desorb from dust grains. Non-thermal desorption mechanisms or gas-phase formation of CH3OH seem 29 to work eciently around IRAS 03245. The fact that IRAS 03245 has the highest bolometric luminosity 30 among the target sources seems to support these mechanisms, in particular the non-thermal desorption 31 mechanisms.