Nothing can emerge from a black hole. Yet, in nature, we find ultra-powerful jets of energy that shoot out from the immediate vicinities of growing black holes. How these jets form remains a puzzle.
In a new study appearing in the journal Nature Astronomy, astronomers announce that they have new clues to this mystery. They studied V404 Cygni – one of the famous black hole binaries in our Galaxy – using the ULTRACAM fast imager mounted on the William Herschel Telescope (WHT), combined with NASA's NuSTAR telescope in Earth orbit, when it was undergoing a bright episode of growth activity during June 2015. They found a fleeting time delay of just 100 milli-seconds (0.1 seconds) between X-rays and optical flashes of light.