title: Heterodyne spectroscopy of the J = 17-16 CO line in Orion.
abstract: We have obtained high-resolution spectra of the 153 micrometers J = 17-16 CO line in the BN-KL region of Orion using a laser heterodyne spectrometer.  The line shows broad wings (30 km s-1 FWHM at BN) characteristic of the plateau emission as well as a narrower component probably associated with the quiescent gas in the molecular ridge.  From an analysis of the plateau emission together with that observed in lower J CO transitions, we derive an excitation temperature of 180 +/- 50 K and minimum column density of 1 x 10(18) cm-2 for CO in this component, which constitutes 80% of the total integrated intensity of the J = 17-16 line near BN.  The peak intensity of the narrower component observed at 0.8 km s-1 resolution increases relative to that of the plateau component toward theta 1C and away from BN, while the width decreases from 10 to 4 km s-1 (FWHM).
authors.affiliation: Space Sciences Laboratory, University of California, Berkeley, USA.
authors.forename: R T
authors.initials: RT
authors.lastname: Boreiko
authors.forename: A L
authors.initials: AL
authors.lastname: Betz
authors.forename: J
authors.initials: J
authors.lastname: Zmuidzinas
mesh_terms: D001256:Astronomy / Q000295:instrumentation*; D002248:Carbon Monoxide; D005118:Extraterrestrial Environment; D005740:Gases / Q000032:analysis; D008962:Models, Theoretical; D016011:Normal Distribution; D013057:Spectrum Analysis / Q000295:instrumentation / Q000379:methods / Q000706:statistics & numerical data; D013696:Temperature
chemical_list: D005740:Gases; D002248:Carbon Monoxide