Anisotropy Studies of Ultra-High Energy Cosmic Rays as Observed by the High Resolution Fly's Eye (HiRes

Abstract. Although the existence of cosmic rays with ener-gies extending to 320 EeV has been confirmed, their ori-gin remains one of the most important questions in parti-cle astrophysics research today. The High–Resolution Fly’s Eye (HiRes) is the largest aperture detector currently col-lecting data from ultra-high energy cosmic ray events. We present for the first time anisotropy studies from monocu-lar and stereo data collected by HiRes. We consider topi-cal candidate sources including the supergalactic plane, the Virgo cluster of galaxies, Cygnus X-3 and the vicinity of the AGASA triplet. We also present the results of searches for density fluctuations as well as autocorrelation studies of cos-mic ray arrival directions in the absence of a priori candidate sources. Finally, we present the results of a search for har-monics in the full-sky event distribution.