Knowledge Bank

The acetylene molecule is important for atmospheric, planetary, and astrophysics applications. In order to improve the knowledge of $C2H2$, systematic measurements of line parameters have been performed. Two main spectral regions have been studied in this work. First, in the $13.6-\mu m$ region, line intensities were revisited for the $\nu 5$ band and determined for some hot bands, allowing us to update the HITRAN database. Second, in the $5-\mu m$ region, numerous line parameters, including positions, intensities, self-broadening coefficients, and self-shifting coefficients of lines belonging to 18 bands were measured for the first time. Intensities were also measured for some new lines in the $4.5-\mu m$ region, and a good agreement was observed between previous measurements. Concerning the $3-\mu m$ region, where two cold bands were already analyzed for positions and intensities, but where the intensities of numerous hot lines are missing in HITRAN, a study is in progress, and preliminary results will be presented.