Left: HGPS significance map (obtained with a correlation radius of 0.1°) with the Fermi-LAT cataloged sources (within 95% uncertainties) overlaid. The blue circle corresponds to the position uncertainty (1σ) of the Fermi-LAT source detected by Guo et al. (2017) above 3 GeV. The H.E.S.S. upper limit on the TeV source extent and the spectral extraction radius R_spec are represented by the dashed and solid yellow circles, respectively. The green contours represent the emission seen by Suzaku between 2 and 8 keV (Suzaku J1427−6051, Fujinaga et al. 2013). The black cross corresponds to the position of 4XMM J142756.7−605214 (see Sect. 3.1.2). Right: MGPS-2 map (843 MHz) toward HESS J1427−608. The red ellipses correspond to the MGPS-2 and PMN cataloged sources outside R_spec, while the cyan and magenta ellipses represent the two MGPS-2 sources inside R_spec. The FWHMof the MGPS-2 is given at the top left of the image. The radio flux extraction region is represented by a white circle (calledR_ON). The yellow circles and green contours are the same as those in the left panel.