Conveners
Astrochemistry I
- Laurent Nahon
The presence of interstellar polycyclic aromatic hydrocarbons (PAHs) is inferred from the widespread mid-infrared (IR) emission bands that are observed at 3.3, 6.2, 7.7, 8.6 and 11.2 μm. [1] This IR radiation is emitted as the PAHs cascade down to the ground state after they have been excited by interstellar (vacuum) ultraviolet radiation. [2] PAHs have been observed towards a large number of...
Titan, the largest moon of Saturn, has a dense atmosphere whose upper layers are mainly composed of methane (CH$_4$) and molecular nitrogen (N$_2$). Their photochemistry leads to the formation of aerosols at very high altitudes (>800 km). Once these aerosols are formed and through their descent towards the surface, they will still interact with persistent UV/VUV radiations, at different...
The interaction of polycyclic aromatic hydrocarbons (PAHs) with UV irradiation is a key process in astrochemistry since it governs the heating of the gas by photoelectric effect and can contribute to the catalytic formation of molecules such as H$_2$ and C$_2$H$_2$. The fragmentation rate of these PAH species also determines their survival in astrophysical environments [1]. In this...
