Orateur
Description
Young stellar objects host strongly magnetised and highly variable plasma environments in which several acceleration processes may generate suprathermal and non-thermal particles. In this talk, I will discuss two complementary regimes of particle acceleration in the star-disc system. The first is associated with large-scale magnetic reconnection during flares in the innermost regions, where impulsive energy release can produce intense bursts of energetic particles. The second is related to turbulence-driven reconnection operating from the inner to intermediate disc regions, where particle acceleration may occur in a more distributed and persistent way.
I will present the physical conditions under which these two mechanisms can operate and the expected properties of the accelerated particle populations. This comparison provides a framework to distinguish between impulsive and continuous sources of non-thermal ionisation in young stellar environments.
I will then show how these particles can affect the chemistry of the inner disc by enhancing ionisation in layers that are important for molecular processing and line formation in the JWST band. In particular, I will discuss how flare-accelerated and turbulence-accelerated particles may modify the abundances of key molecules in the warm inner disc, and how these changes could translate into observable signatures in infrared molecular tracers. More broadly, the aim is to connect kinetic plasma processes in young stellar objects with their chemical and observational consequences, and to assess whether energetic particles accelerated by flares and turbulent reconnection should be considered as an important ingredient of inner-disc physics.