VARIATION OF C/N AND C/H RATIOS OF TITAN'S AEROSOLS ANALOGUES

摘要

Under the action of the solar radiations and electrons from Saturn's magnetosphere, the gaseous phase of Titan's atmosphere leads to organic aerosols production. The composition of these aerosols on Titan is still unknown, in part due to its complexity. Many experimental simulations have been performed by irradiating N_2:CH_4 gas mixtures with different energy sources in order to reproduce the chemistry of gas and paniculate phases (for a review see Ref. [2]). Even if functional groups of aerosols analogues have been determined using spectroscopy and pyrolysis, their building molecules still remain difficult to identify. However this chemical composition is a key information for Cassini-Huygens experiments in the frame of Titan's atmospheric modeling. We present the first results of the variation of C/N and C/H ratios related to different parameters of experimental simulations of Titan's atmosphere. These data will allow to constraint photochemical models, in order for them to be more realistic. Then the understanding of the mechanism of aerosols formation on Titan as a function of altitude will be easier.