| Résumé | The Fourier transform spectrum of CH3OH in the 10μm region has been re-examined at higher pressure and path length than heretofore, as part of a program to provide comprehensive CH3OH spectral data for astrophysical and atmospheric applications. With the increase in spectral sensitivity, it has been possible to assign new torsionally excited v12=1 and v12=2 subbands plus further high-K, v12=0 subbands of the v8 CO-stretching band. Upper-state term values have been determined, and have been fitted to J(J+1) power-series expansions in order to obtain the excited v8 substate origins. A variety of weaker subbands from other modes has also been identified in the 10μm spectrum including v12=0, v12=1, and v12=0<--1 torsional subbands of the v7 in-plane CH3 rock, v12=0<--1 and v12=0<--2 torsional combination subbands of the v6 OH bend, and v12=0<--2 subbands of the v5 symmetric CH3 bend. Line intensities have been retrieved line-by-line from the spectra. A large set of "unperturbed" v8 transitions has been modeled using the same type of multi-parameter effective Hamiltonian employed successfully for the ground state, with inclusion of the intensities of a subset of the stronger v8 spectral lines in the fitting in order to obtain appropriate transition dipole terms. Together, a 10μm methanol database in HITRAN format has been generated. |
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