TS map (in sigma units), in celestial coordinates, of the region around the PWN HESS J1825-137 in the energy range between 1 GeV and 1 TeV. The red circle and star indicate the 2D-Gaussian extension and centroid fit obtained in this work. The red dashed circles mark the uncertainty on the 2D-Gaussian extension. The green and white circles correspond to the extension obtained in the FGES catalogue (Ackermann et al. 2017a) and in Grondin et al. (2011), respectively. The black point indicates the position of PSR J1826-1334, the pulsar which is believed to power the nebula. The 4FGL sources, as well as the three candidate sources added in the model, are represented with light grey points.