The 12 micron band of ethane - High-resolution laboratory analysis with candidate lines for infrared heterodyne searches

Abstract

Emission from the ν<SUB>9</SUB> band of ethane at 12 μm has been reported in the spectra of Jupiter, Saturn, Neptune, and Titan. This paper reports the results of a laboratory study of ν<SUB>9</SUB> using both high-resolution Fourier transform and diode laser absorption spectroscopy. Approximately 2000 transitions in this band have been subjected to an analysis that includes the normal rovibrational terms as well as higher order effects. A model for this band capable of reproducing observed ν<SUB>9</SUB> features to better than 0.001 cm<SUP>-1</SUP> is presented. High-precision values of the primary ground-state constants have also been determined. A list of ν<SUB>9</SUB> transitions occurring near <SUP>14</SUP>CO<SUB>2</SUB> laser lines that are good candidates for laser heterodyne searches has been compiled.