Speaker
Description
Extreme particle acceleration usually involves magnetic fields and thus is inevitably accompanied by synchrotron emission from the accelerated particles.
Measurement of this emission, including its polarization, can break model degeneracies and place important constraints on the physical mechanisms operating in a pevatron source.
I will briefly review some of the constraints and then specialize to galactic sources, which have typical magnetic fields in the micro- to milli-Gauss range. For a PeV electron gyrating in such fields, its synchrotron emission lands approximately in the ~0.1 - 10 MeV range, unfortunately known as the "MeV gap" due to the current lack of space instrumentation that works in this energy range. I will discuss future missions and concepts such as COSI, GRAMS, and MEGAT that attempt to fill this energy coverage gap, and the sensitivity levels they need to reach in order to provide meaningful constraints.
