Hadronic Production of Gamma Rays and Starburst Galaxies

Understand

The Milky Way has been estabished to emit gamma rays.

• These gamma rays are presumably dominated by decays of neutral pions, although inverse Compton scatterings and bremsstrahlung also contribute.
• It is plausible that other galaxies can be diffuse sources of gamma rays in a similar manner.
• Starburst galaxies are particularly interesting to study as they are expected to have much higher cosmic-ray fluxes and interstellar matter densities.