INVESTIGADORES
WAHLBERG Hernan Pablo
artículos
Título:
Searches for Large-Scale Anisotropy in the Arrival Directions of Cosmic Rays Detected above Energy of 1019 eV at the Pierre Auger Observatory and the Telescope Array
Autor/es:
PIERRE AUGER COLLABORATION, HERNAN WAHLBERG
Revista:
ASTROPHYSICAL JOURNAL
Editorial:
IOP PUBLISHING LTD
Referencias:
Lugar: Londres; Año: 2014
ISSN:
0004-637X
Resumen:
Spherical harmonic moments are well-suited for capturing anisotropy at any scale in the flux
of cosmic rays. An unambiguous measurement of the full set of spherical harmonic coefficients
requires full-sky coverage. This can be achieved by combining data from observatories located
in both the northern and southern hemispheres. To this end, a joint analysis using data recorded
at the Telescope Array and the Pierre Auger Observatory above 1019 eV is presented in this
work. The resulting multipolar expansion of the flux of cosmic rays allows us to perform a series
of anisotropy searches, and in particular to report on the angular power spectrum of cosmic rays
above 1019 eV. No significant deviation from isotropic expectations is found throughout the
analyses performed. Upper limits on the amplitudes of the dipole and quadrupole moments are
derived as a function of the direction in the sky, varying between 7% and 13% for the dipole
and between 7% and 10% for a symmetric quadrupole.