0.05° and divide the whole energy range (300 MeV – 300 GeV) into 30 bins. We use version 10 of the `Science Tools` (v10r0p5) and the `P8R2_V6` Instrument Response Functions (IRFs) with the `SOURCE` event class for the following analysis[^1]. The resulting count map of the 10° $\times$ 10° region centered on the position of the SNR is shown in Figure \[fig:Cmap\].

The $\gamma$-ray data around the source are modeled starting with the $\textit{Fermi}$-LAT 3FGL source catalog [@3FGL], complemented by the extended source FGES J1553.8$-$5325[^2] [@FGES:Pass8]. We first fit the point sources and extended sources within a 10° radius (additionally accounting for the most significant sources between 10° and 15°) simultaneously with the Galactic and isotropic diffuse emissions described by the files `gll_iem_v06.fits` [@GIEM_Fermi:2016] and `iso_P8R2_SOURCE_V6_v06_PSF3.txt` respectively [^3]. We then compute a residual test statistic (TS) map to search for additional sources.

The TS is defined to test the likelihood of one hypothesis $\mathcal{L}_1$ (including a source) against the null hypothesis $\mathcal{L}_0$ (absence of source), such that: $$\hspace{2.5cm} \textrm{TS} = 2 \times (\log{\mathcal{L}_1 } - \log{\mathcal{L}_0})  \label{eq:TS}$$ This can be directly interpreted in terms of significance of hypothesis $1$ with respect to the null hypothesis $0$ in which the TS 