Evidence of intermediate-scale energy spectrum anisotropy of cosmic rays E≥10.sup.19.2./sup. eV with the Telescope Array surface detector

0502260 - FZÚ 2019 RIV US eng J - Journal Article
Abbasi, R.U. - Abe, M. - Abu-Zayyad, T. - Urban, Federico … Total 139 authors
Evidence of intermediate-scale energy spectrum anisotropy of cosmic rays E≥10^19.2 eV with the Telescope Array surface detector.
Astrophysical Journal. Roč. 862, č. 2 (2018), s. 1-6, č. článku 91. ISSN 0004-637X. E-ISSN 1538-4357
R&D Projects: GA MŠMT EF15_003/0000437
Grant - others:OP VVV - CoGraDS(XE) CZ.02.1.01/0.0/0.0/15_003/0000437
Institutional support: RVO:68378271
Keywords : astroparticle physics * cosmic rays * large-scale structure of universe
OECD category: Particles and field physics
Impact factor: 5.580, year: 2018

Evidence for an intermediate-scale energy spectrum anisotropy has been found in the arrival directions of ultra-high energy cosmic rays for energies greater than 10(19.2) eV in the northern hemisphere using 7 years of Telescope Array surface detector data. A relative energy distribution test is done comparing events inside oversampled spherical caps of equal exposure, to those outside, using the Poisson likelihood ratio. The center of maximum significance is at 9(h)16(m), 45 degrees, and has a deficit of events with energies 10(19.2) <= E < 10(19.75) eV and an excess for E >= 10(19.75) eV. The post-trial probability of this energy anisotropy, appearing by chance anywhere on an isotropic sky, is found by Monte Carlo simulation to be 9 x 10(-5) (3.74 sigma(global)).
Permanent Link: http://hdl.handle.net/11104/0294206