“Lightning” Flash In Black Hole
by Lisa Winter
Photo credit: MAGIC Collaboration
For the first time, astronomers have discovered “lightning” coming from a supermassive black hole. The scientists with the European Very-Long-Baseline Interferometry Network (VLBI) observed a short—yet intense—burst of gamma radiation that formed abnormally fast from galaxy IC 310. The massive collaboration included astronomers from twelve countries, and the results were published in Science.
The radio galaxy IC 310 is located about 260 million light years away in the Perseus constellation. Researchers observed the galaxy’s black hole with Major Atmospheric Gamma-ray Imaging Cherenkov Telescopes (MAGIC) in the Canary Islands. MAGIC is a pair of 17-meter telescopes that measure high-energy gamma radiation, and this system is the largest in the world for this type of research.
With the high-detailed view MAGIC provided, the scientists discovered a stream of gamma radiation extending past the supermassive black hole in the center of the galaxy that appeared and dissipated five times faster than can be explained under ordinary circumstances.
“The event horizon of the black hole—the surface space-time from which nothing can escape the black hole, not even light—is three times higher than the distance between the Earth and the Sun; that is, 450 millions of kilometers. Light needs 25 minutes to cover that distance,” co-author Eduardo Ros of the Max Planck Institute for Radioastronomy said in a press release.
The team then suspected that the the source of the radiation was coming from somewhere else. The black hole was previously discovered to have an active galactic nucleus (AGN), which is a small region that spins very rapidly and has a magnetic field. These AGNs can spew out huge amounts of radiation almost as quickly as the speed of light.
“We believe that in the black hole’s polar regions there are huge electric fields, which are able to accelerate fundamental particles at relativist speeds, in a way that when they interact with others of lower energy, are able to produce highly energized gamma rays,” Ros continued. “We can imagine this process as a fierce electrical thunderstorm.”
These fields build up energy over a period of time, which then needs to be discharged. The area where this energy accumulates is roughly the size of our solar system, which means that the burst of radiation that discharges is extremely fast and bright. Using MAGIC, this team was able to provide the first inside look into the mechanics of this phenomenon.
“When we observe black holes at high energies, we are looking into the galactic nucleus to very great depths. We are trying to look directly into the machinery at the centre, as it were,” project leader Razmik Mirzoyan of the Max Planck Institute for Physics explained in a press release.
Emission mode: A black hole in rotation produces a magnetic field (red). In polar regions (yellow), enormous electrical fields appear and accelerate the particles at relativist speeds which are able to produce very energetic gamma ray as well as to shoot the jets thousands and even millions of light years away.