What is the the origin of ultra-high energy cosmic rays?
These particles should originate from outside the Milky Way, and their direction of propagation can be deflected by magnetic fields outside our galaxy. Only if the magnetic fields outside the Milky Way are below a certain level, the trajectories of ultra-high energy cosmic rays remain rectilinear enough to point towards their exact sources. But predicting the exact strength and topology of these magnetic fields is non trivial, as it requires advanced numerical simulations.
We are combining ENZO-MHD simulations to in order to
the
CRPropa code
to predict the deflection of UHECRs by possible extragalactic magnetic fields, also employing constrained simulations of the Local Universe.