Impact of using the ultrahigh-energy cosmic ray arrival energies to constrain source associations
File(s)
Published version
Author(s)
Capel, Francesca
Mortlock, Daniel J
Type
Journal Article
Abstract
We present a Bayesian hierarchical model which enables a joint fit of the ultrahigh-energy cosmic ray (UHECR) energy spectrum and arrival directions within the context of a physical model for the UHECR phenomenology. In this way, possible associations with astrophysical source populations can be assessed in a physically and statistically principled manner. The importance of including the UHECR energy data and detection effects is demonstrated through simulation studies, showing that the effective GZK horizon is significantly extended for typical reconstruction uncertainties. We also verify the ability of the model to fit and recover physical parameters from crpropa 3 simulations. Finally, the model is used to assess the fraction of the publicly available data set of 231 UHECRs detected by the Pierre Auger Observatory which are associated with the Fermi-LAT 2FHL catalogue, a set of starburst galaxies, and Swift-BAT hard X-ray sources. We find association fractions of 9.5+2.4−5.9, 22.7+6.6−12.4, and 22.8+6.6−8.0 per cent for the 2FHL, starburst galaxies, and Swift-BAT catalogues respectively.
Date Issued
2019-04-01
Date Acceptance
2018-12-29
Citation
Monthly Notices of the Royal Astronomical Society, 2019, 484 (2), pp.2324-2340
ISSN
0035-8711
Publisher
Oxford University Press (OUP)
Start Page
2324
End Page
2340
Journal / Book Title
Monthly Notices of the Royal Astronomical Society
Volume
484
Issue
2
Copyright Statement
© 2019 The Author(s). All rights reserved.
Sponsor
Science and Technology Facilities Council
Science and Technology Facilities Council (STFC)
Science and Technology Facilities Council (STFC)
Grant Number
ST-N000838
ST/N000838/1
ST/S000372/1
Subjects
0201 Astronomical And Space Sciences
Astronomy & Astrophysics
Publication Status
Published
Date Publish Online
2019-01-10