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Title: DISCOVERY OF THE METHOXY RADICAL, CH{sub 3}O, TOWARD B1: DUST GRAIN AND GAS-PHASE CHEMISTRY IN COLD DARK CLOUDS

Journal Article · · Astrophysical Journal Letters
; ;  [1];  [2];  [3];  [4]
  1. Department of Astrophysics, CAB, INTA-CSIC, Crta Torrejon, E-28850 Torrejon de Ardoz, Madrid (Spain)
  2. NRAO, 520 Edgemont Road, Charlottesville, VA 22902 (United States)
  3. Luth, Observatoire de Paris, CNRS UMR8102, Place J. Janssen F-92190 Meudon (France)
  4. LERMA, Observatoire de Paris, CNRS UMR8112 and Ecole Normale Superieure, 61 avenue de l'observatoire, F-75014 Paris (France)

We report on the discovery of the methoxy radical (CH{sub 3}O) 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 (CH{sub 3}SH), formic acid (HCOOH), propynal (HCCCHO), acetaldehyde (CH{sub 3}CHO), dimethyl ether (CH{sub 3}OCH{sub 3}), methyl formate (CH{sub 3}OCOH), and the formyl radical (HCO). The column density of all these species is {approx_equal}10{sup 12} cm{sup -2}, corresponding to abundances of {approx_equal}10{sup -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 CH{sub 3}O isomer released to the gas phase is CH{sub 2}OH rather than the methoxy one. Possible gas-phase formation routes to CH{sub 3}O from OH and methanol are discussed.

OSTI ID:
22078432
Journal Information:
Astrophysical Journal Letters, Vol. 759, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
Country of Publication:
United States
Language:
English