Richard Riehle

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Several proposed source models for Ultra-High Energy Cosmic Rays (UHECRs) consist of dipole distributions oriented towards major astrophysical landmarks such as the galactic center, M87, or Centaurus A. We use a comparison between real data and simulated data to show that the HiRes-I monocular data for energies above 10 18.5 eV is, in fact, consistent with(More)
The High Resolution Fly's Eye (HiRes) experiment has observed the Greisen-Zatsepin-Kuzmin suppression (called the GZK cutoff) with a statistical significance of five standard deviations. HiRes' measurement of the flux of ultrahigh energy cosmic rays shows a sharp suppression at an energy of 6 x 10(19) eV, consistent with the expected cutoff energy. We(More)
The High Resolution Fly's Eye (HiRes) experiment has observed the GZK cutoff. HiRes' measurement of the flux of cosmic rays shows a sharp suppression at an energy of 6 × 10 19 eV, exactly the expected cutoff energy. We observe the " Ankle " of the cosmic ray spectrum as well, at an energy of 4 × 10 18 eV. We describe the experiment, data collection,(More)
We present the results of a search for cosmic ray point sources at energies above 4.0 × 10 19 eV in the combined data sets recorded by the AGASA and HiRes stereo experiments. The analysis is based on a maximum likelihood ratio test using the probability density function for each event rather than requiring an a priori choice of a fixed angular bin size. No(More)
In this paper we investigate the possible existence of multi-point correlation in the arrival direction of the UHECR events detected by the High Resolution Fly's Eye (HiRes) stereo detector. Multi-point correlations could result from the deflection of UHECRs by galactic and intergalactic magnetic fields, and the subsequent dispersion of arrival directions(More)
The High Resolution Fly's Eye (HiRes) experiment is an air fluorescence detector which, operating in stereo mode, has a typical angular resolution of 0.6 • and is sensitive to cosmic rays with energies above 10 18 eV. HiRes is thus an excellent instrument for the study of the arrival directions of ultrahigh energy cosmic rays. We present the results of a(More)
We have searched for correlations between the pointing directions of ultrahigh energy cosmic rays observed by the High Resolution Fly's Eye experiment and Active Galactic Nuclei (AGN) visible from its northern hemisphere location. No correlations, other than random correlations, have been found. We report our results using search parameters prescribed by(More)