CRIME - cosmic ray interactions in molecular environments
Résumé
Molecular clouds act as targets for cosmic rays (CR), revealing their presence through either gamma-ray emission due to proton-proton interactions, and/or through the ionization level of several chemicals in the cloud, produced by the CR flux. The ionization rate is a unique tool, to some extend complementary to the gamma-ray emission, in that it allows to estimate the CR spectrum especially for energies below the pion production rate ( 270 MeV). Here we study the effect of ionization on H2 clouds due to both CR protons and electrons, using the fully relativistic ionization cross sections, which is important to correctly account for the contribution due to relativistic CRs. The contribution to ionization due to secondary electrons is also included self-consistently. The whole calculation has been implemented into a numerical code which is publicly accessible through a web-interface. The code also include the calculation of gamma-ray emission once the CR spectrum (electrons and/or protons) have been specified.