J = 2-1 CO observations of molecular clouds with high-velocity gas - Evidence for clumpy outflows

Abstract

view Abstract Citations (69) References (41) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS J=2-1 CO observations of molecular clouds with high-velocity gas : evidence for clumpy outflows. Plambeck, R. L. ; Snell, R. L. ; Loren, R. B. Abstract Spectra are presented of the J = 2-1 and J = 1-0 transitions of (C-12)O toward seven regions where high-velocity molecular gas and vibrationally excited H2 emissions are seen. The two CO lines were observed with similar telescope beamwidths, so that the 2-1 and 1-0 transitions probe the same volume of gas. In all the sources, including Orion, the data indicate that the 2-1 CO lines are optically thick even in the high-velocity gas. In order to account for the low CO antenna temperatures observed in the line wings, the high-velocity gas can fill only a small fraction of the telescope beam. Since many of the regions of high-velocity gas are known to be extended relative to the beam, the CO emission must arise from numerous small, high-velocity condensations. This result provides possible observational support for the 'interstellar bullet' models of Norman and Silk, (1979), or for Chevalier's (1980) clumpy outflow model of Orion. Publication: The Astrophysical Journal Pub Date: March 1983 DOI: 10.1086/160781 Bibcode: 1983ApJ...266..321P Keywords: Carbon Monoxide; Electron Transitions; Interstellar Gas; Molecular Clouds; Molecular Spectra; Nebulae; Brightness Temperature; Early Stars; Line Spectra; Molecular Excitation; Vibrational Spectra; Astrophysics full text sources ADS | data products SIMBAD (11) NED (1)