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Title: DISCOVERY OF METHYL ACETATE AND GAUCHE ETHYL FORMATE IN ORION

Abstract

We report on the discovery of methyl acetate, CH{sub 3}COOCH{sub 3}, through the detection of a large number of rotational lines from each one of the spin states of the molecule: AA species (A{sub 1} or A{sub 2}), EA species (E{sub 1}), AE species (E{sub 2}), and EE species (E{sub 3} or E{sub 4}). We also report, for the first time in space, the detection of the gauche conformer of ethyl formate, CH{sub 3}CH{sub 2}OCOH, in the same source. The trans conformer is also detected for the first time outside the Galactic center source SgrB2. From the derived velocity of the emission of methyl acetate, we conclude that it arises mainly from the compact ridge region with a total column density of (4.2 {+-} 0.5) Multiplication-Sign 10{sup 15} cm{sup -2}. The derived rotational temperature is 150 K. The column density for each conformer of ethyl formate, trans and gauche, is (4.5 {+-} 1.0) Multiplication-Sign 10{sup 14} cm{sup -2}. Their abundance ratio indicates a kinetic temperature of 135 K for the emitting gas and suggests that gas-phase reactions could participate efficiently in the formation of both conformers in addition to cold ice mantle reactions on the surface of dust grains.

Authors:
; ; ;  [1]; ;  [2]
  1. Department of Astrophysics, CAB, INTA-CSIC, Crta Torrejon-Ajalvir, km. 4, E-28850 Torrejon de Ardoz, Madrid (Spain)
  2. Laboratoire Interuniversitaire des Systemes Atmospheriques, CNRS/IPSL UMR7583 et Universites Paris Diderot et Paris Est, 61 av. General de Gaulle, F-94010 Creteil (France)
Publication Date:
OSTI Identifier:
22118785
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal Letters
Additional Journal Information:
Journal Volume: 770; Journal Issue: 1; 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; ABUNDANCE; ASTRONOMY; ASTROPHYSICS; COSMIC DUST; DENSITY; DETECTION; EMISSION; FORMATES; ICE; METHYL ACETATE; MILKY WAY; MOLECULES; SPACE; SPIN

Citation Formats

Tercero, B., Cernicharo, J., Lopez, A., Caro, G. M. Munoz, Kleiner, I., and Nguyen, H. V. L.,. DISCOVERY OF METHYL ACETATE AND GAUCHE ETHYL FORMATE IN ORION. United States: N. p., 2013. Web. doi:10.1088/2041-8205/770/1/L13.
Tercero, B., Cernicharo, J., Lopez, A., Caro, G. M. Munoz, Kleiner, I., & Nguyen, H. V. L.,. DISCOVERY OF METHYL ACETATE AND GAUCHE ETHYL FORMATE IN ORION. United States. doi:10.1088/2041-8205/770/1/L13.
Tercero, B., Cernicharo, J., Lopez, A., Caro, G. M. Munoz, Kleiner, I., and Nguyen, H. V. L.,. Mon . "DISCOVERY OF METHYL ACETATE AND GAUCHE ETHYL FORMATE IN ORION". United States. doi:10.1088/2041-8205/770/1/L13.
@article{osti_22118785,
title = {DISCOVERY OF METHYL ACETATE AND GAUCHE ETHYL FORMATE IN ORION},
author = {Tercero, B. and Cernicharo, J. and Lopez, A. and Caro, G. M. Munoz and Kleiner, I. and Nguyen, H. V. L.,},
abstractNote = {We report on the discovery of methyl acetate, CH{sub 3}COOCH{sub 3}, through the detection of a large number of rotational lines from each one of the spin states of the molecule: AA species (A{sub 1} or A{sub 2}), EA species (E{sub 1}), AE species (E{sub 2}), and EE species (E{sub 3} or E{sub 4}). We also report, for the first time in space, the detection of the gauche conformer of ethyl formate, CH{sub 3}CH{sub 2}OCOH, in the same source. The trans conformer is also detected for the first time outside the Galactic center source SgrB2. From the derived velocity of the emission of methyl acetate, we conclude that it arises mainly from the compact ridge region with a total column density of (4.2 {+-} 0.5) Multiplication-Sign 10{sup 15} cm{sup -2}. The derived rotational temperature is 150 K. The column density for each conformer of ethyl formate, trans and gauche, is (4.5 {+-} 1.0) Multiplication-Sign 10{sup 14} cm{sup -2}. Their abundance ratio indicates a kinetic temperature of 135 K for the emitting gas and suggests that gas-phase reactions could participate efficiently in the formation of both conformers in addition to cold ice mantle reactions on the surface of dust grains.},
doi = {10.1088/2041-8205/770/1/L13},
journal = {Astrophysical Journal Letters},
issn = {2041-8205},
number = 1,
volume = 770,
place = {United States},
year = {2013},
month = {6}
}