Probing the Galactic cosmic ray flux with submillimeter and gamma ray data

The study of Galactic diffuse $\gamma$ radiation combined with the knowledge of the distribution of the molecular hydrogen in the Galaxy offers a unique tool to probe the cosmic ray flux in the Galaxy. A methodology to study the level of the cosmic ray "sea" and to unveil target-accelerator systems in the Galaxy, which makes use of the data from the high resolution survey of the Galactic molecular clouds performed with the NANTEN telescope and of the data from gamma-ray instruments, has been developed. Some predictions concerning the level of the cosmic ray "sea" and the $\gamma$-ray emission close to cosmic ray sources for instruments such as Fermi and Cherenkov Telescope Array are presented.