Cosmic Rays, Gamma-ray Bursts, and their simple understanding

Alvaro De Rújula
CERN and Boston University


I shall discuss non-solar cosmic rays (CRs) and long-duration gamma-ray bursts (GRBs). Of the various interpretations of these phenomena, the one supported by the data is the following. Accreting black holes and neutron stars are observed to launch relativistic puffs of plasma: `cannonballs' (CBs). The inner domain of a rotating star whose core has collapsed resembles such an accreting system. This suggests that core-collapse supernovae emit CBs, as SN1987A did. The observable properties of a CB as it exits a supernova and travels in space can be studied as a function of the CB's mass and energy, and of `ambient' properties: the encountered matter- and light- distributions, the composition of the former, and the location of intelligent observers. The latter will conclude that the interactions of CBs with ambient matter and light generate CRs and GRBs, all of whose properties can be described by this `CB model' with very predictive success, very few parameters, and very simple physics.