Abstract book - Prof. Per Jensen, Ph.D. - Bergische Universität ...

Poster session, H42 155He-, N 2 - and O 2 -broadening coefficients of sulfur dioxide rovibrationallines in the 9.2 µm regionNicola Tasinato 1 , Andrea Pietropolli Charmet 1 , Paolo Stoppa 1 , Santi Giorgianni 11 Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia,Calle Larga S. Marta 2137, I-30123 Venezia, Italy, tasinato@unive.itTasinato N.Pietropolli CharmetStoppa P.Giorgianni S.Besides being a trace gas relevant for the atmospheric chemistry, sulfur dioxide is also amolecule of proven astrophysical importance. In the Earth's atmosphere it activelyenters in the sulfur cycle and it is one of the main causes of acid rains, while it has alsobeen identified in the interstellar medium, particularly in star forming regions.Due to this twofold interest, the collisional line broadening of sulfur dioxide perturbedby helium, nitrogen and oxygen has been investigated for several ro-vibrationaltransitions belonging to the P and Q branches of the ν 1 normal mode around 9 µm. Thespectra of foreign-perturbed SO 2 have been acquired with a tunable diode laserspectrometer at room temperature varying the gas buffer pressure in the range 5 - 90mbar. The analysis of the recorded spectra has led to the determination of He-, N 2 - andO 2 -broadening coefficients. Among the perturbers considered in this study, N 2 providesthe most efficient collisional relaxation while He produces the weakest damping. SO 2 -air broadening coefficients have also been determined from those obtained for SO 2perturbed by nitrogen and oxygen. Concerning the dependence of the broadeningcoefficients upon the quantum numbers, the present results suggest a weak dependenceon J, while more data are needed in order to assess the K a trend. Work in this directionis in progress.