TEMPERATURE-DEPENDENCE OF BROADENING AND SHIFTS OF METHANE LINES IN THE NU(4) BAND

We have recorded high-resolution absorption spectra of methane broadened by dry air and by N2 at temperatures from -63 to 41-degrees-C using a Fourier transform spectrometer. These spectra have been analyzed to determine pressure broadening and line-shift coefficients, along with their temperature dependences, for 148 lines in the V4 fundamental band of (CH4)-C-12. The experimental uncertainties for lines with J" less-than-or-equal-to 10 are generally <2% for the broadening coefficient b(L)0, 6-12% for its temperature dependence exponent n, 6-20% for the line-shift coefficient delta0, and 20-40% for its temperature dependence coefficient delta'; for J" > 10 the experimental uncertainties are somewhat larger. These results, especially for N2-broadening, are in excellent agreement with other recent measurements. Since the present results cover a wide range of rotational quantum numbers (J" up to 14), the variation of the temperature dependence of the half-widths and shifts from line to line within the nu4 band is also examined.