Ionisation as indicator for cosmic ray acceleration

Astrospheres and wind bubbles of massive stars are believed to be sources of cosmic rays with energies \(E\lesssim 1\,\)TeV. These particles are not directly detectable, but their impact on surrounding matter, in particular ionisation of atomic and molecular hydrogen, can lead to observable signatures. A correlation study of both gamma ray emission, induced by proton-proton interactions of cosmic ray protons with kinetic energies \(E_\mathrm{p}\ge 280\,\)MeV with ambient hydrogen, and ionisation induced by cosmic ray protons of kinetic energies \(E_\mathrm{p}< 280\,\)MeV can be performed in order to study potential sources of (sub)TeV cosmic rays.