Testing a reported correlation between arrival directions of ultrahigh-energy cosmic rays and a flux pattern from nearby starburst galaxies using Telescope Array data

Abstract

The Pierre Auger Collaboration (Auger) recently reported a correlation between the arrival directions of cosmic rays with energies above 39 EeV and the flux pattern of 23 nearby starburst galaxies (SBGs). In this Letter, we tested the same hypothesis using cosmic rays detected by the Telescope Array experiment (TA) in the 9-year period from May 2008 to May 2017. Unlike the Auger analysis, we did not optimize the parameter values but kept them fixed to the best-fit values found by Auger, namely 9.7% for the anisotropic fraction of cosmic rays assumed to originate from the SBGs in the list and 12.9° for the angular scale of the correlations. The energy threshold we adopted is 43 EeV, corresponding to 39 EeV in Auger when taking into account the energy-scale difference between two experiments. We find that the TA data is compatible with isotropy to within 1.1σ and with the Auger result to within 1.4σ, meaning that it is not capable to discriminate between these two hypotheses.

arXiv commentMore accurate title, fixed an inconsistency in the declination range used, with a few figures slightly changing as a result, other minor revisions

References in corpus (10)

• The Pierre Auger Cosmic Ray Observatory
• The surface detector array of the Telescope Array experiment
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Cited by in corpus (35)

• Open Questions in Cosmic-Ray Research at Ultrahigh Energies
• Ultra-High-Energy Cosmic Rays
• Arrival Directions of Cosmic Rays above 32 EeV from Phase One of the Pierre Auger Observatory
• An extremely energetic cosmic ray observed by a surface detector array
• POEMMA's Target of Opportunity Sensitivity to Cosmic Neutrino Transient Sources
• Cosmic Ray Models
• ASTRI Mini-Array Core Science at the Observatorio del Teide
• The Imprint of Large Scale Structure on the Ultra-High-Energy Cosmic Ray Sky
• Ultra-High-Energy Tau Neutrino Cross Sections with GRAND and POEMMA
• Performance and science reach of POEMMA for ultrahigh-energy particles
• Search for Large-scale Anisotropy on Arrival Directions of Ultra-high-energy Cosmic Rays Observed with the Telescope Array Experiment
• Are starburst galaxies a common source of high energy neutrinos and cosmic rays?
• Search for Spatial Correlations of Neutrinos with Ultra-High-Energy Cosmic Rays
• UHECR arrival directions in the latest data from the original Auger and TA surface detectors and nearby galaxies
• IceCube Neutrinos from Hadronically Powered Gamma-Ray Galaxies
• Full-sky searches for anisotropies in UHECR arrival directions with the Pierre Auger Observatory and the Telescope Array
• Covering the celestial sphere at ultra-high energies
• Stellar Mass and Star Formation Rate within a Billion Light-Years
• Impact of using the ultra-high-energy cosmic ray arrival energies to constrain source associations
• Ultrahigh-Energy Cosmic Ray Composition from the Distribution of Arrival Directions
• Search for magnetically-induced signatures in the arrival directions of ultra-high-energy cosmic rays measured at the Pierre Auger Observatory
• Exploring the superwind mechanism for generating ultrahigh-energy cosmic rays using large-scale modeling of starbursts
• Shining ALP Dark Radiation
• The prototype X-ray binary GX 339-4: using TeV gamma-rays to assess LMXBs as Galactic cosmic ray accelerators
• Feasibility of Correlated Extensive Air Shower Detection with a Distributed Cosmic Ray Network
• Nearby active galactic nuclei and starburst galaxies as sources of the measured UHECRs anisotropy signal
• Evidence for UHECR origin in starburst galaxies
• Modification of the Dipole in Arrival Directions of Ultra-high-energy Cosmic Rays due to the Galactic Magnetic Field
• Cross-correlating 2MRS galaxies with UHECR flux from Pierre Auger Observatory
• Investigating an angular correlation between nearby starburst galaxies and UHECRs with the Telescope Array experiment
• Effects of galactic magnetic field on the UHECR correlation studies with starburst galaxies
• On gamma rays as predictors of UHECR flux in AGNs
• Beyond the Local Void: A data-driven search for the origins of the Amaterasu particle
• Propagation of ultra-high-energy cosmic rays in the magnetized cosmic web
• Echoes of the past: ultra-high energy cosmic rays accelerated by radio galaxies, scattered by starburst galaxies