Correlation of pulsar positions and the arrival directions of air showers of energies 10¹⁷-10¹⁸ eV observed at Chacaltaya

A plot of the declination against right ascension of 2598 observed air showers has been divided into a grid of 5 degrees declination against 5 degrees right ascension. A distribution of the number of showers along each declination band is then constructed. In each declination band those groups of showers (bins within the grid) which are above 2 standard deviations in the distribution are selected for further analysis. There are 36 such groups and among these 19 coincide with the known positions of pulsars while 7.5 are expected from accidental coincidence. The results obtained from this preliminary analysis do not rule out the possibility that some at least of the cosmic ray primaries in the energy range studied originate in pulsars.