Photochemical processes on Titan: Irradiation of mixtures of gases that simulate Titan's atmosphere

Determination of the complex refractive indices of Titan haze analogs using photothermal deflection spectroscopy

“…4. Previously reported infrared spectral studies demonstrated that the solid product formed by photolysis had a carbonyl band at 1703 cm À1 assigned to a keto group (Tran et al, 2008). The k(k) plot of the data obtained by PDS measurements is almost identical with that of analog I except for the value at 1550 nm in the near infrared.…”

“…Tran et al (2003aTran et al ( , 2008 reported the index of refraction of the polymer formed by irradiating various gas mixtures containing nitrogen, methane, and some minor hydrocarbons (acetylene, ethylene), nitriles (hydrogen cyanide, cyanoacetylene) and oxygen-bearing species (carbon monoxide) present in Titan's atmosphere. While plasma sources intend to reproduce the effect of Saturn's magnetospheric electrons and extreme UV (EUV) photons that are deposited in Titan's upper atmosphere, the UV light source used by Tran et al (2003aTran et al ( , 2008 is representative of the far UV (FUV) photons that penetrate deep into Titan's stratosphere. Photolysis takes place throughout the flow reactor because the low mixing ratios of the light-absorbing gases used results in the absorption of only 10 À4 of the UV flux being absorbed.…”

Laboratory Studies on the Irradiation of Methane in Interstellar, Cometary, and Solar System Ices

“…Coustenis et al (2003) have analyzed the atmosphere of Saturn's moon Titan using ISO and found that not only are methane, ethane, ethylene, and acetylene present, but also more complex hydrocarbons such as propane, propyne, benzene, allene, and diacetylene. Most modeling of Titan is focused on attempting to recreate these molecules from gas-phase processes initiated by UV irradiation (e.g., Tran et al 2005); however, it is clear that the surface is known to be bombarded by energetic ions, photons and electrons that are capable of producing more complex molecules in the solid state. A proportion of these may well be released into the gas phase and need to be incorporated into these models.…”

The millimetre-wave rotational spectrum of phenylacetylene

“…It can also be formed by photochemical reactions from acetylene [3], vinylacetylene [4], or 1,3-butadiene [5]. Phenylacetylene has been formed in a mixture of gases simulating the atmosphere of Saturn's moon Titan [6], and studies in Refs. [1,4,5] were, in fact, also motivated by the desire to explore the rich hydrocarbon chemistry expected to be present on Titan.…”