Speaker
Description
Contrary to what had been hoped a quarter of a century ago, pointing astronomy with ultra-high-energy cosmic rays (UHECR) has remained elusive, despite considerable increase in statistics. The reason is most probably due to much larger deflections than anticipated under the assumption that most UHECRs would be protons, as well as a possibly much larger number of contributing sources. While it is now firmly established that the flux of UHECR is not isotropic, exactly what can be deduced from the anisotropy observations regarding the UHECR sources and acceleration mechanism is unclear, and sometimes overestimated. We will assess the situation in the light of the uncertainties on the Galactic magnetic fields, notably regarding the possible magnification/demagnification of sources in the region of the Virgo galaxy cluster, and examining both statistical and cosmic variances. Finally, we will discuss potentially new observables associated with the evolution of the various signals with energy, and examine how the situation could evolve with larger statistics and a more uniform full-sky coverage.
