Astron. Astrophys. 320, L5-L8 (1997)

3. Results

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.

Table 1. Statistics of the Mkn 501, Crab Nebula and OFF source datasets. The number of expected events after all cuts is found from the OFF source data ( in Section 2).

Fig. 1. The ON-source - OFF-source ALPHA distributions. ALPHA is a measure of the deviation of the shower axis from the source direction. For Mkn 501 there are 351 excess candidates after all cuts (shaded, rate 2.4 h-1 with a significance of 5.2 ). For the Crab Nebula there are 186 excess candidates (8.1 h-1) with a significance of 7.6 .

© European Southern Observatory (ESO) 1997

Online publication: June 30, 1998
helpdesk.link@springer.de