Speaker
Prof.
Enrique Zas
(IGFAE - University of Santiago)
Description
The overall picture of the highest energy particles produced in the Universe
is changing because of measurements made with the Pierre Auger Observatory.
Composition studies point towards an unexpected mixed composition of
intermediate mass nuclei, more isotropic than anticipated, which is
reshaping the future of the field and underlining the priority to understand
composition at the highest energies.
The Observatory is competitive in the search for neutrinos of all flavours
above about 100 PeV by looking for very inclined showers produced deep in the
atmosphere by neutrinos interacting either in the atmosphere or in the Earth's
crust and covering a declination field of view between $-65^\circ$ and
$60^\circ$ in equatorial coordinates.
Neutrinos are produced in ultra high energy cosmic ray interactions and they
provide valuable complementary information, their fluxes being sensitive to the
primary cosmic ray masses and their directions reflecting the source positions.
We report the results of the neutrino search providing competitive bounds
to neutrino production and strong constraints to a number of production models
including cosmogenic neutrinos due to ultra high energy protons. We also
report on two recent contributions of the Observatory to multimessenger studies.
The correlations of the directions of the highest energy astrophysical neutrinos
discovered with IceCube and the highest energy cosmic rays detected with the
Auger Observatory and the Telescope Array, and the targeted search for
neutrinos correlated with the discovery of the gravitational-wave events
GW150914 and GW151226 discovered with advanced LIGO.
Primary author
Prof.
Enrique Zas
(IGFAE - University of Santiago)
