The spectrum of acetylene in the 5-μm region from new line-parameter measurements

Abstract

Abstract Using Fourier Transform spectra (unapodized FWHM: 0.002 cm −1 ) of acetylene 12C2H2, absolute line positions have been obtained in the 5-μm region for about 490 lines belonging to 15 hot bands arising from the v4=1 or v5=1 lower vibrational level, improving the data available in this spectral region. Absolute line intensities have been measured for about 410 lines, from which vibrational transition dipole moments squared could be determined, as well as empirical Herman-Wallis coefficients when it was possible. The self-broadening coefficients of more than 370 lines have been measured at room temperature, showing that no vibrational dependence exists for the bands of acetylene already studied, and allowing a significant determination of their rotational dependence. Furthermore, about 120 measured values of self-shifting coefficients are tentatively proposed. Combining results published for other bands, and using the smoothed line-parameter values obtained in this work, a HITRAN-format line list of the acetylene molecule has been set up in this spectral region.