A Yardstick for Measuring Astrophysical Jets



What we detected:Super-fast visible light flickering from a bright outbursting black hole V404 Cygni in 205. (Images from WHT/ULTRACAM, analysed by the authors).


Our interpretation:The visible light flares were analysed together with X-ray and radio data. The optical flares are delayed by 100 milliseconds with respect to X-ray flares from close to the black hole. Visible light emission from the bright flare in the jet sets the size scale over which inner plasma is accelerated to close to light speed in these extreme jets. (Illustration Credit: Robert Hurt).




Importance:The distance that we have constrained (about 0.1 light-seconds) does not come out of the relevant jet models, but can be fed back to refine them. In addition, it appears that supermassive black hole jets may show similar delays when adjustments are made for their higher black masses (Animation Credit: Gabriel Perez Diaz; IAC; for higher quality full animation, click here).




Read our full Nature Astronomy paper here.
(This is the authors' version. The final published version should be available on www.nature.com/natastron and here late on Oct 23.)


Last year, we had a press release reporting raging red flares from this source, which you can also read here: Astronomers see black hole raging red.