Table 2: HEGRA IACT system direction reconstruction algorithms and cuts used for the 1ES 1959+650 signal search and for the spectral analysis, respectively. The resulting numbers for 4 selected subsets are given: "2000/2001'' including all data used for the first 5.2 $\sigma $ detection, "May 2002'' only using data from the nights May 18/19 and May 19/20, 2002 (see Fig. 1). The "low state'' resp. "high state'' data sets are used for the spectral analysis (see text and Fig. 3).
  signal spectrum
stereo algorithm #3 #3
number of images per event      $\ge$3 $\ge$3
shape cut on   mscw <1.1 <1.1
angular distance cut  $\Theta ^2$ <0.012 deg2 <0.014 deg2
$\alpha = A_{\mbox{\tiny ON}}/A_{\mbox{\tiny OFF}}$ 0.0758 0.1429
  2000/2001 " low state''
${T}_{\mbox{\tiny obs}}$ 93.8 h 149.6 h
$N_{\mbox{\tiny ON}}$ 354 585
$N_{\mbox{\tiny OFF}}$ 3441 1960
$N_{\mbox{\tiny$\gamma$ -candidates}}$ 93 $\pm$ 19 305 $\pm$ 25
significance ($\sigma $) 5.2 14.6
  May 2002 " high state''
${T}_{\mbox{\tiny obs}}$ 3.6 h 8.5 h
$N_{\mbox{\tiny ON}}$ 179 275
$N_{\mbox{\tiny OFF}}$ 131 141
$N_{\mbox{\tiny$\gamma$ -candidates}}$ 169 $\pm$ 13 255 $\pm$ 17
significance ($\sigma $) 23.4 25.5


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