| Literature DB >> 11540080 |
P Friberg1, S C Madden, A Hjalmarson, W M Irvine.
Abstract
We report observations, for the first time, of the 2(0) - 1(0)A+ and E, 2(-1) - 1(-1) E, and 1(0) - 0(0)A+ lines of methanol (CH3OH) in three dark cold clouds, TMC1, L134N, and B335. The CH3OH emission is extended in these clouds and shows a complex velocity structure. Clear indications of non LTE excitation are observed in TMC 1. Estimated column densities are a few 10(13) cm-2. Although less abundant than formaldehyde (H2CO), methanol is almost an order of magnitude more abundant than acetaldehyde (CH3CHO), in these clouds. Dimethyl ether was searched for in L134N, to an upper limit of 4 10(12) cm-2 (3 sigma). Implications for dark cloud excitation and chemistry are discussed. A new, more accurate, rest frequency 96741.39(0.01) MHz is determined for the 2(0) - 1(0) A+ E line of methanol.Entities:
Keywords: NASA Discipline Exobiology; NASA Discipline Number 52-10; NASA Program Exobiology; Non-NASA Center
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Year: 1988 PMID： 11540080
Source DB: PubMed Journal: Astron Astrophys ISSN： 0004-6361 Impact factor: 5.802