The irregular galaxy NGC 5408 viewed by the NASA/ESA Hubble Space Telescope.
The galaxy is located some 16 million light-years away and hosts a very bright source of X-rays, NGC 5408 X-1.
NGC 5408 X-1 is an ultra-luminous X-ray source – a binary system consisting of a stellar remnant that is feeding on gas from a companion star at an especially high rate.
Scientists using ESA's XMM-Newton have discovered gas streaming away at a quarter of the speed of light from NGC 5408 X-1 and another bright X-ray binary, NGC 1313 X-1, confirming that these sources conceal a compact object accreting matter at extraordinarily high rates.