Black Holes are known to swallow everything coming in their path but that's not the end. With time they they emit enormous amounts of energy.
In 2015 Hubble Telescope captured something that shocked the entire world. It was a burst of plasma jet 260 million light years away in space coming from an unknown source. Calculations showed that the jet was travelling at 98% the speed of light.
Scientists finally concluded that they have captured a plasma burst coming from a super-massive Black Hole. Which is located inside a galaxy 260 million light-years away.