This is slide 5 of 60 from the EXOSAT slide set. The following caption is the one originally provided with the slide set.
A colour representation of the 2-6 keV X-ray emission from the galactic plane. The map constructed from a series of scanning observations with the medium-energy detector, covers a region from approximately +50° to -50° of galactic longitude. X-ray emission from numerous point sources is shown together with a narrow ridge (in green) of emission extending along the galactic plane on either side of galactic centre.