Production of H2CO3, H2O2 and O3 on frozen Solar System surfaces by heavy solar wind particles and cosmic rays analogs.
Abstract
The presence of carbonic acid (H2 CO3 ), hydrogen peroxide (H2 O2 ) and ozone (O3 ) is a direct evidence of radiation processing of frozen surfaces in astrophysical environments. These species have been observed at several frozen moons of giant planets (e.g. Europa, Ganymede, Rhea, Dione). Carbonic acid has been observed at Calisto and its presence on Mars surface has been suggested. This acid is a potential reactant to form biologically important molecules like oxalic acid and also has geochemical implications such as the precipitation of carbonates in aqueous solutions, being of great interest to astrochemists and astrobiologists. Precursor compounds of these species, such as water and carbon dioxide, have also been largely detected among icy surfaces suck as the moons of giant planets, outer Solar System objects and comets. We present experimental studies about the production of H2 O2 , O3 and H2 CO3 from the pro-cessing of pure (H2 O and CO2 ) and mixed (H2 O:CO2 ) ices by heavy, highly-charged, and energetic ions (46 MeV 58 Ni13+ ). The experiments simulate the physical chemistry induced by heavy-ion cosmic rays and solar wind particles at icy Solar System surfaces. The mea-surements were performed inside a high vacuum chamber at the heavy-ion accelerator GANIL (Grand Accelerateur National d'Ions Lourds) in Caen, France. The gas samples were deposited onto a polished CsI substrate previously cooled to 13 K. In-situ analysis was performed by a Fourier transform infrared spectrometer (FTIR) at different ion fluences. The formation cross sections of the radiolysis products have been determined and compared with literature data, their implications for the chemistry on frozen Solar System surfaces are discussed.
- Publication:
-
38th COSPAR Scientific Assembly
- Pub Date:
- 2010
- Bibcode:
- 2010cosp...38.3269P