Ellis Owen

Energetic particles (cosmic rays) can interact with interstellar molecular clouds. Some types of these particles can undergo interactions which
decay to emit high energy electromagnetic radiation (gamma-rays), while other types can lose their energy and cool down via processes which emit radiation at radio frequencies. The propagation of these energetic particles through molecular clouds is regulated
by the structure of the internal cloud magnetic fields, while the fields themselves influence the evolution of the cloud, and it’s route towards star-formation. The first section explains that it is valuable to study these magnetic fields, as they have an
important role in regulating star-formation. Probing their strength and structure can reveal new information about the role they play in the initial phases of star-formation. However, given the high densities and obscuration, it is difficult to do this by
conventional methods. Section 2 introduces the possibility of using multi-wavelength observations as a new alternative. Section 3 then details the theory: first, the transport equation must be solved to determine the cosmic ray density and corresponding high
and low energy emission from the clouds. In particular, the diffusion of cosmic rays through the magnetic field is considered in more detail in section 4, where a method of estimating the ability of cosmic rays to diffuse based on the magnetic structures observed
is proposed. Section 5 then shows how the emission signatures can be calculated, if the distribution of cosmic rays is know, while section 6 discusses how this may be observed with current and up-coming instruments (the Square Kilometer Array and the Atacama
Large Millimetre Array for the low-energy emission, or the Cherenkov Telescope Array for the high-energy emission).