HAWK-I image in the H₂ filter. Panel a (left) is the subtracted image and the Spitzer archive image in the background, which confirms at a larger scale that the bright residual in the bottom left quadrant is an astrophysical feature. We used contours to highlight the relevant arm-like structure that is present in the Spitzer image, but missing in the HAWK-I image. Panel b (right) is a zoom centered on the field of view of HAWK-I. GX 301-2 is marked in the two images. Contours correspond to the 4.5 µm surface brightness: 100 and 230 MJy sr⁻¹.