A Bayesian analysis of the 69 highest energy cosmic rays detected by the Pierre Auger Observatory
File(s)stw1165.pdf (2.3 MB)
Published version
Author(s)
Khanin, Alexander
Mortlock, Daniel J
Type
Journal Article
Abstract
The origins of ultrahigh energy cosmic rays (UHECRs) remain an open question. Several attempts have been made to cross-correlate the arrival directions of the UHECRs with catalogues of potential sources, but no definite conclusion has been reached. We report a Bayesian
analysis of the 69 events, from the Pierre Auger Observatory (PAO), that aims to determine the fraction of the UHECRs that originate from known AGNs in the Veron-Cety & Verson (VCV) catalogue, as well as AGNs detected with the Swift Burst Alert Telescope (Swift-BAT),
galaxies from the 2MASS Redshift Survey (2MRS), and an additional volume-limited sample of 17 nearby AGNs. The study makes use of a multilevel Bayesian model of UHECR injection, propagation and detection. We find that for reasonable ranges of prior parameters the
Bayes factors disfavour a purely isotropic model. For fiducial values of the model parameters, we report 68 per cent credible intervals for the fraction of source originating UHECRs of 0.09+0.05 −0.04, 0.25+0.09 −0.08, 0.24+0.12 −0.10, and 0.08+0.04 −0.03 for the VCV, Swift-BAT and 2MRS catalogues, and the sample of 17 AGNs, respectively.
analysis of the 69 events, from the Pierre Auger Observatory (PAO), that aims to determine the fraction of the UHECRs that originate from known AGNs in the Veron-Cety & Verson (VCV) catalogue, as well as AGNs detected with the Swift Burst Alert Telescope (Swift-BAT),
galaxies from the 2MASS Redshift Survey (2MRS), and an additional volume-limited sample of 17 nearby AGNs. The study makes use of a multilevel Bayesian model of UHECR injection, propagation and detection. We find that for reasonable ranges of prior parameters the
Bayes factors disfavour a purely isotropic model. For fiducial values of the model parameters, we report 68 per cent credible intervals for the fraction of source originating UHECRs of 0.09+0.05 −0.04, 0.25+0.09 −0.08, 0.24+0.12 −0.10, and 0.08+0.04 −0.03 for the VCV, Swift-BAT and 2MRS catalogues, and the sample of 17 AGNs, respectively.
Date Issued
2016-05-16
Date Acceptance
2016-05-12
Citation
Monthly Notices of the Royal Astronomical Society, 2016, 460 (3), pp.2765-2778
ISSN
0035-8711
Publisher
Oxford University Press (OUP)
Start Page
2765
End Page
2778
Journal / Book Title
Monthly Notices of the Royal Astronomical Society
Volume
460
Issue
3
Copyright Statement
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society © 2016 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
Sponsor
Science and Technology Facilities Council
Science and Technology Facilities Council (STFC)
Grant Number
ST-N000838
ST/N000838/1
Subjects
Science & Technology
Physical Sciences
Astronomy & Astrophysics
methods: statistical
cosmic rays
ACTIVE GALACTIC NUCLEI
ARRIVAL DIRECTIONS
SPECTRUM
ANISOTROPY
CENTAURUS
SEARCH
ARRAY
Publication Status
Published