CRIME - cosmic ray interactions in molecular environments

Abstract

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 sev- eral 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 ioniza- tion 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.