Knowledge Bank

High-resolution $(0.01cm-1)$ room-temperature spectra of 13CH4 diluted with dry air were obtained in the $2700-3200cm-1$ spectral region using the McMath Fourier transform spectrometer at the National Solar Observatory on Kitt Peak. A 99% 13C-enriched methane diluted to a mixing ration of approximately 0.01 was used in a 5 cm absorption path to record the data. The total sample pressures used were approximately 75, 150, 300 and 500 Torr. A nonlinear least-squares spectral fitting technique was ued in determining the halfwidth coefficients and positions. The derived halfwidth coefficients and pressure shifts will be compared to vales obtained for identical transitions in the $\nu 3$ band of $\mathrm{<mrow\; data-mjx-texclass="ORD">12</mrow>}CH4$ as well as to those in the $\nu 4$ band of $\mathrm{<mrow\; data-mjx-texclass="ORD">13</mrow>}CH4$.