Influence of temperature on the spectral profile of spectral lines of spherical rotors

This project consists to study the temperature dependence of spectral profiles of lines belonging to spherical rotator molecules as methane (CH₄). By diode-laser spectroscopy and using absorption cells operating at low temperatures (from 77K to 300K), we determine molecular parameters of the observed lines (intensity, broadenings, line mixing ...) with their temperature variations, for atmospheric and planetary data and databanks.