Table 4: Fit results for different spectral models. The fit range is chosen from 0.3 to 113 TeV. The differential flux normalisation I0 is given in units of $10^{-12} ~ {\rm cm}^{-2} ~ {\rm s}^{-1} ~ {\rm TeV}^{-1}$. Shown are a power-law model (row 1), a power law with an exponential cutoff (row 2, 3, 4; the cutoff energy $E_{\rm c}$ is given in TeV), a power law with an energy dependent photon index (row 5), and a broken power law (row 6; in the formula, the parameter S = 0.6 describes the sharpness of the transition from $\Gamma _1$ to $\Gamma _2$ and it is fixed in the fit). Note that when fitting a broken power law to the data, some of the fit parameters are highly correlated.

Fit Formula		 Fit Parameters $\chi^2$ (d.o.f.)

$I_0\ E ^ {-\Gamma}$		 $I_0 = 20.5 \pm 0.4$ $\Gamma = 2.32 \pm 0.01$     145.6 (25)
  $I_0 = 21.3 \pm 0.5$ $\Gamma = 2.04 \pm 0.04$ $E_{{\rm c}} = 17.9 \pm 3.3 $ $\beta = 1.0$ 39.5 (24)
$I_0\ E ^ {-\Gamma}\ \exp\left(- ( E / E_{{\rm c}})^\beta\right)$ $I_0 = 34.1 \pm 2.5$ $\Gamma = 1.79 \pm 0.06$ $E_{{\rm c}} = 3.7 \pm 1.0 $ $\beta = 0.5$ 34.3 (24)
  $I_0 = 40.5 \pm 1.5$ $\Gamma = 1.74 \pm 0.02$ $E_{{\rm c}} = 2.3 \pm 0.2 $ $\beta = 0.45$ 34.2 (24)

$I_0\ E ^ {-\Gamma + ~ \beta\ \log E}$		 $I_0 = 20.6 \pm 0.5$ $\Gamma = 2.02 \pm 0.04$ $\beta = -0.29 \pm 0.03 $   38.8 (24)

$I_0\ \left(E / E_{{\rm B}} \right) ^ {-\Gamma_1}\ \left( 1 + ( E / E_{{\rm B}} ) ^ {1 / S } \right) ^ {~ S ~ (\Gamma_1 - \Gamma_2)}$		 $I_0 = 0.5 \pm 0.4$ $\Gamma_1 = 2.00 \pm 0.05$ $\Gamma_2 = 3.1 \pm 0.2$ $ E_{{\rm B}} = 6.6 \pm 2.2 $ 29.8 (23)


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