Cosmic Ray Acceleration and Scattering in a 3d MHD Model of Compact Massive Star Clusters

Compact young massive star clusters (YMSCs) contain dozens of O-, B-, and WR-type stars with powerful, fast winds within a radius of ~1 pc. In the turbulent environment of such clusters, particle acceleration by ensembles of shock waves and compression/rarefaction waves is possible. This work investigates the propagation and acceleration of particles in YMSCs using three-dimensional magnetohydrodynamic (MHD) simulations with the open source code PLUTO and its built-in module for solving the equations of motion for test charged particles. It is found that in the cluster core, near the termination shocks of O-star winds, as well as at the collective wind termination shock, protons are accelerated to energies ≳100 TeV. The spatial and energy distributions of the particles are discussed.