Knowledge Bank

In view of the recent observation of the $949cm-1$ fundamental band of ethylene in the atmospheres of Saturn and Titan made by the IRIS instrument on board the Voyager I spacecraft, we have studied this band as well as the $1443cm-1$ band at temperatures of 150K, 200K, and 296K, in the laboratory at NASA-Amea using a Nicolet interferometer-spectrometer and a cold cell developed at Stony Brook. Using nitrogen to broaden the rotational lines, the band strengths have been measured at 296K under conditions for which the rotational structure is smeared out. Using these results for the absolute intensities of the bands and the already published rotational analysis of these bands, we have made a comparison of a line-by-line calculation with our lower pressure spectra of the $C2H4$ nitrogen-broadened lines at temperatures of 150K, 200K, and 296K.