A Northern Sky Survey for Point-Like Sources of EeV Neutral Particles with the Telescope Array Experiment

Abstract

We report on the search for steady point-like sources of neutral particles around 10${}^{18}$ eV between 2008 May and 2013 May with the scintillator surface detector of the Telescope Array experiment. We found overall no significant point-like excess above 0.5 EeV in the northern sky. Subsequently, we also searched for coincidence with the Fermi bright Galactic sources. No significant coincidence was found within the statistical uncertainty. Hence, we set an upper limit on the neutron flux that corresponds to an averaged flux of 0.07 km${}^{-2}$ yr${}^{-1}$ for $E>1$ EeV in the northern sky at the 95% confidence level. This is the most stringent flux upper limit in a northern sky survey assuming point-like sources. The upper limit at the 95% confidence level on the neutron flux from Cygnus X-3 is also set to 0.2 km${}^{-2}$ yr${}^{-1}$ for $E>0.5$ EeV. This is an order of magnitude lower than previous flux measurements.

arXiv comment27 pages, 10 figures, 3 tables, accepted for publication in the Astrophysical Journal

References in corpus (13)

• Fermi Large Area Telescope Bright Gamma-ray Source List
• The surface detector array of the Telescope Array experiment
• Indications of Intermediate-Scale Anisotropy of Cosmic Rays with Energy Greater Than 57 EeV in the Northern Sky Measured with the Surface Detector of the Telescope Array Experiment
• New air fluorescence detectors employed in the Telescope Array experiment
• The Cosmic Ray Energy Spectrum Observed with the Surface Detector of the Telescope Array Experiment
• Milagro Observations of Multi-TeV Emission from Galactic Sources in the Fermi Bright Source List
• A Search for Point Sources of EeV Neutrons
• Multi-TeV Gamma-Ray Flares from Markarian 421 in 2000 and 2001 Observed with the Tibet Air Shower Array
• Search for Anisotropy of Ultra-High Energy Cosmic Rays with the Telescope Array Experiment
• Dethinning Extensive Air Shower Simulations
• Search for correlations of the arrival directions of ultra-high energy cosmic ray with extragalactic objects as observed by the telescope array experiment
• Observation of TeV Gamma Rays from the Fermi Bright Galactic Sources with the Tibet Air Shower Array
• Search for Point-Like Sources of Cosmic Rays with Energies above 10^18.5 eV in the HiRes-I Monocular Data-Set

Cited by in corpus (7)

• A targeted search for point sources of EeV photons with the Pierre Auger Observatory
• Ultrahigh energy cosmic rays and neutrinos from light nuclei composition
• Prospects for a Multi-TeV Gamma-ray Sky Survey with the LHAASO Water Cherenkov Detector Array
• Search for point sources of ultra-high energy photons with the Telescope Array surface detector
• Search for Sources of High Energy Neutrons with Four Years of Data from the IceTop Detector
• The influence of the observatory latitude on the study of ultra high energy cosmic rays
• Insights on the mass composition of ultrahigh-energy cosmic rays from small-scale anisotropy with large-scale structure simulations