Search for Point Sources of Ultra–High‐Energy Cosmic Rays above 4.0 x 10¹⁹eV Using a Maximum Likelihood Ratio Test

Abstract

We present the results of a search for cosmic ray point sources at energies above 40 EeV 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 statistically significant clustering of events consistent with a point source is found.