Thinkshop 2020

The influence of magnetic fields in protoplanetary disk evolution depends sensitively on the level of ionisation present. Protoplanetary disks are thought to be only very weakly ionised which provides imperfect coupling to magnetic fields and influences disk dynamics. Understanding the sources of ionisation, such as cosmic rays, present in the disks underpins our overall understanding of how these systems evolve and form planets.

However, young solar-type stars are very magnetically active and drive stronger stellar winds that may shield protoplanetary disks from galactic cosmic rays, thus losing an important source of ionisation. At the same time, the increased magnetic activity of young stars suggests that protoplanetary disks, and young exoplanetary systems, are bombarded by stellar cosmic rays, or stellar energetic particles. I will present recent results from our model of cosmic ray transport in these systems and the chemical signatures that we might expect from cosmic rays.