Table 1 shows the event statistics. The number of expected events and the statistical significances are calculated according to the procedure described in Section 2. We obtain an excess of 351 events after all cuts with a significance of 5.2 . For comparison, 23 h of observations of the Crab Nebula taken between October 1995 and February 1996 at were analysed. Using the same procedure as for Mkn 501, we find an excess of 186 events with a significance of 7.6 . The ALPHA distributions for Mkn 501 and the Crab Nebula are shown in Figure 1.
© European Southern Observatory (ESO) 1997
Online publication: June 30, 1998