Production of Hydronium Ion (H3O)+ and Protonated Water Clusters (H2O)nH+ After Energetic Ion Bombardment of Water Ice in Astrophysical Environments

Water ice exists on many objects in space. The most abundant icy species, among them water, are present in the icy satellites of the outer Solar System giant planets. The nucleus of comets, which is mainly composed of water ice, is another example of its abundance. In the interstellar medium (ISM), ice mantles, formed by molecular species sticking on dust grains, consist mainly of water ice. All these objects are exposed to ionizing radiation like ions, UV photons and electrons. Sputtering of atoms, molecules, ions and radicals from icy surfaces may populate and maintain exospheres of icy objects in the Solar System. In other respect, ionized hydrides such as OH+, H2O+ and H3O+ have been detected in the gas-phase in star forming regions. Interactions with cosmic rays could be an additional explanation to the current models for the formation of those species. In fact, laboratory simulations showed that the main components of the sputtered ionic species from water ice are oxygen hydrides. In this work, wate...