Charged Particle Trajectories in the Local Superbubble

Abstract

In this thesis we study the propagation of cosmic rays (CR) emitted by sources in the Local Superbubble (LB). There are many bursting sources of CRs inside the LB which may be modelled as a continuous injection of CRs, and therefore we study the LB's effect on CRs by calculating trajectories of individual protons from both a continuous and a bursting source within two models of the LB's magnetic field. These models are constructed using information from literature, each having a regular and random component for which we assume equipartition of energy. We find that the escape time $t_{\rm{esc}}(E)$ has a knee-like feature around $E/Z= 5\cdot 10^{15}$ eV for coherence lengths of the random field smaller than the LB's radius. Additionally, we find that $t_{\rm{esc}}(E)\propto E^{-\alpha}$ for energies $E\leq 2\cdot 10^{15}$ eV where $\alpha$ was calculated to be $\alpha=0.354\pm0.008$. The results are not entirely conclusive and we would have to run more simulations to validate that the knee-like feature stems from the bubble itself.