Princeton University Astroplasmas Seminar

I will summarize what is known about UHECRs.  The observations are in fact highly constraining.  The rigidity distribution (R==E/Ze) of UHECRs is observed to be very narrow which rules out the most popular source scenarios.  This feature follows naturally, however, for Binary Neutron Star mergers.   I will discuss evidence that UHECR acceleration occurs not in the jets but in the magnetized turbulent outflow, including the successful prediction of the shape and location of the spectral cutoff and smoking-gun tests of the composition.