Conclusions

We have examined the use of the two point angular autocorrelation function in the analysis of directional data concerning the highest energy cosmic rays. We have done this with data from the SUGAR air shower array in anticipation of data becoming available, and requiring interpretation, from the Pierre Auger observatory within a few years. The process was to identify any possible clustering in the directional data. We recognise that in the future, this identification must be based on predetermined criteria. The next step is to examine the direction of any clustering in comparison with a preselected catalogue of potential sources.

We find some evidence for clustering in the arrival directions contained in the SUGAR data and that clustering is related in direction to three potential source objects in a catalogue which we had chosen. These were an FR II radio source, a cluster of galaxies containing a strong radio source, and a very large cluster of galaxies which has already been suggested as a possible source of the highest energy cosmic rays.

© Copyright Astronomical Society of Australia 1997