Thermal Electrons in Mildly-relativistic Synchrotron Blast-waves

Understand

Numerical models of collisionless shocks robustly predict an electron distribution comprised of both thermal and non-thermal electrons.

• Here, we explore in detail the effect of thermal electrons on the emergent synchrotron emission from sub-relativistic shocks.
• We present a complete `thermal + non-thermal' synchrotron model and derive properties of the resulting spectrum and light-curves.
• Using these results we delineate the relative importance of thermal and non-thermal electrons for sub-relativistic shock-powered synchrotron transients.