INVESTIGADORES
TUEROS Matias Jorge
artículos
Título:
A search for anisotropy in the arrival directions of ultra high energy cosmic rays recorded at the Pierre Auger Observatory
Autor/es:
THE PIERRE AUGER COLLABORATION (AUTOR 434 DE 474); M. TUEROS
Revista:
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
Editorial:
IOP PUBLISHING LTD
Referencias:
Lugar: Londres; Año: 2012 vol. 40 p. 1 - 22
ISSN:
1475-7516
Resumen:
Observations of cosmic ray arrival directions made with the Pierre Auger
Observatory have previously provided evidence of anisotropy at the 99%
CL using the correlation of ultra high energy cosmic rays (UHECRs) with
objects drawn from the Véron-Cetty Véron catalog. In this paper we
report on the use of three catalog independent methods to search for
anisotropy. The 2ptL, 2pt+ and 3pt methods, each giving a different
measure of self-clustering in arrival directions, were tested on mock
cosmic ray data sets to study the impacts of sample size and magnetic
smearing on their results, accounting for both angular and energy
resolutions. If the sources of UHECRs follow the same large scale
structure as ordinary galaxies in the local Universe and if UHECRs are
deflected no more than a few degrees, a study of mock maps suggests that
these three methods can efficiently respond to the resulting anisotropy
with a P-value = 1.0% or smaller with data sets as few as 100
events. Using data taken from January 1, 2004 to July 31, 2010 we
examined the 20,30,...,110 highest energy events with a corresponding
minimum energy threshold of about 49.3 EeV. The minimum P-values
found were 13.5% using the 2pt-L method, 1.0% using the 2pt+ method and
1.1% using the 3pt method for the highest 100 energy events. In view
of the multiple (correlated) scans performed on the data set, these
catalog-independent methods do not yield strong evidence of anisotropy
in the highest energy cosmic rays.