TS maps for the region around NGC 4151; in all panels the green cross shows the location of NGC 4151 and the orange cross the location of source S. In all panels only the 3FGL sources were subtracted from the maps, except for panel b), where an additional point source was added at the position of NGC 4151. a) The 8° × 8° degrees region with a pixel size of . The map was built for the energy range 0.2–30 GeV, neglecting period S (see text); the red and white crosses indicate the location of 3FGL sources. b) The same as in a), but the model includes a point source at the position of NGC 4151 to compensate for the residual seen in a). c) The degree region with a pixel size of 0.̊075 for 0.2–30 GeV for period S. d) The region with a pixel size of 0.̊075 for 0.2–6 GeV and the full period of 6.4 years; the black cross shows the location of a point source found with gtfindsrc under the assumption that the residual seen in the map is produced by a single source; source S is not seen in this map because photons with E> 10 GeV are excluded.