Adaptively smoothed EPIC-PN image of diffuse X-ray flux in the 3–7 keV energy band with a linear color scale (arbitrary units). The instrument FoV is shown as a dashed circle (green). The large ellipses (black) denote the extraction regions for HESS J1626−490 and the background test, respectively. The large circle (magenta) to the east gives the approximate extension of the X-ray scattering halo of 4U 1624-490. Excluded regions are shown as crossed-out areas (yellow regions crossed with red lines).