Detection of complex organic molecules in young starless core L1521E

ABSTRACT Determining the level of chemical complexity within dense starless and gravitationally bound pre-stellar cores is crucial for constructing models, which subsequently constrain initial conditions star formation. We have searched complex organic molecules (COMs) in young core L1521E, report first clear detection dimethyl ether (CH3OCH3), methyl formate (HCOOCH3), vinyl cyanide (CH2CHCN). Eight transitions acetaldehyde (CH3CHO) were also detected, five (A states) used to determine an excitation temperature then calculate column densities other oxygen-bearing COMs. If source size was not taken into account (i.e. if filling fraction assumed be one), density underestimated, thus we stress need higher resolution mapping data. calculated L1521E COM abundances compared them stages low-mass formation, finding similarities starless/pre-stellar cores, suggesting related evolution. The scenario that assumes formation COMs gas-phase reactions between precursors formed on grains ejected cold gas via reactive desorption tested unable reproduce observed abundances, with exception CH3CHO. These results suggest are by alone, but through surface interstellar grains. Our observations present a new, unique challenge existing theoretical astrochemical models.