On the Origin of Ultrahigh Energy Cosmic Rays

by Noemie Globus

at Physics Colloquium

Tue, 22 May 2018, 15:30
Nanotechnology institute building (#51) room 15

Abstract

Cosmic rays are one of the most fascinating yet surprisingly common phenomena in the universe They consist of energetic particles with an out of equilibrium power law spectrum extending over at least eleven orders of magnitude in energy from 1 GeV to 10 11 GeV In the past few years new measurements by experiments such as KASCADE Grande the Pierre Auger observatory and Telescope Array have greatly improved our knowledge of the highest energy domain of the cosmic ray spectrum Recent Auger composition analyses suggest a composition getting gradually heavier above a few 10 18 eV I review the recent observations and show that the observational data can be explained by a generic model having only one Galactic component and one extragalactic component The key to the success of this model is that the protons emitted by the extragalactic sources have a different spectrum from the other types of nuclei as we recently showed to be expected in highly magnetised and photon rich environments such as the relativistic jets associated with GRB or AGN I will discuss multi messenger constrains brought by neutrino and gamma ray experiments and discuss the possible extragalactic origin of the UHECR dipole anisotropy recently reported by Auger

Created on 13-05-2018 by Bar Lev, Yevgeny (ybarlev)
Updaded on 13-05-2018 by Bar Lev, Yevgeny (ybarlev)