2012ApJ...759L..43C

We report on the discovery of the methoxy radical (CH₃O) toward the cold and dense core B1-b based on the observation, with the IRAM 30 m radio telescope, of several lines at 3 and 2 mm wavelengths. Besides this new molecular species we also report on the detection of many lines arising from methyl mercaptan (CH₃SH), formic acid (HCOOH), propynal (HCCCHO), acetaldehyde (CH₃CHO), dimethyl ether (CH₃OCH₃), methyl formate (CH₃OCOH), and the formyl radical (HCO). The column density of all these species is ≃10¹²/cm2, corresponding to abundances of ≃10^–11. The similarity in abundances for all these species strongly suggest that they are formed on the surface of dust grains and ejected to the gas phase through non-thermal desorption processes, most likely cosmic rays or secondary photons. Nevertheless, laboratory experiments indicate that the CH₃ O isomer released to the gas phase is CH₂ OH rather than the methoxy one. Possible gas-phase formation routes to CH₃ O from OH and methanol are discussed.