Smoothed γ-ray residual (i.e. 4FGL 0959.6+4606 is not included in the analysis model file) TS map with a scale of 1.5° ×1.5° and 0.03° per pixel, extracted from the 15-month Fermi-LAT data. The green and cyan circles correspond to the 95% C.L. γ-ray localisation uncertainty region of the 15-month period and entire data set, respectively. The green and pink X-shaped markers are radio positions of candidate B and candidate A, respectively.