skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

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

Abstract

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.

Authors:
; ;  [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)
Publication Date:
OSTI Identifier:
22078432
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal Letters
Additional Journal Information:
Journal Volume: 759; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 2041-8205
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACETALDEHYDE; COSMIC RADIATION; DENSITY; DUSTS; FORMIC ACID; FORMYL RADICALS; METHANOL; METHOXY RADICALS; METHYL ETHER; RADIO TELESCOPES; SUPERNOVAE; THIOLS

Citation Formats

Cernicharo, J., Jimenez-Escobar, A., Munoz Caro, G. M., Marcelino, N., Roueff, E., and Gerin, M., E-mail: jcernicharo@cab.inta-csic.es. DISCOVERY OF THE METHOXY RADICAL, CH{sub 3}O, TOWARD B1: DUST GRAIN AND GAS-PHASE CHEMISTRY IN COLD DARK CLOUDS. United States: N. p., 2012. Web. doi:10.1088/2041-8205/759/2/L43.
Cernicharo, J., Jimenez-Escobar, A., Munoz Caro, G. M., Marcelino, N., Roueff, E., & Gerin, M., E-mail: jcernicharo@cab.inta-csic.es. DISCOVERY OF THE METHOXY RADICAL, CH{sub 3}O, TOWARD B1: DUST GRAIN AND GAS-PHASE CHEMISTRY IN COLD DARK CLOUDS. United States. doi:10.1088/2041-8205/759/2/L43.
Cernicharo, J., Jimenez-Escobar, A., Munoz Caro, G. M., Marcelino, N., Roueff, E., and Gerin, M., E-mail: jcernicharo@cab.inta-csic.es. Sat . "DISCOVERY OF THE METHOXY RADICAL, CH{sub 3}O, TOWARD B1: DUST GRAIN AND GAS-PHASE CHEMISTRY IN COLD DARK CLOUDS". United States. doi:10.1088/2041-8205/759/2/L43.
@article{osti_22078432,
title = {DISCOVERY OF THE METHOXY RADICAL, CH{sub 3}O, TOWARD B1: DUST GRAIN AND GAS-PHASE CHEMISTRY IN COLD DARK CLOUDS},
author = {Cernicharo, J. and Jimenez-Escobar, A. and Munoz Caro, G. M. and Marcelino, N. and Roueff, E. and Gerin, M., E-mail: jcernicharo@cab.inta-csic.es},
abstractNote = {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.},
doi = {10.1088/2041-8205/759/2/L43},
journal = {Astrophysical Journal Letters},
issn = {2041-8205},
number = 2,
volume = 759,
place = {United States},
year = {2012},
month = {11}
}