A lightning inferno at the event horizon of a massive black hole

Results published by the Science journal on November 6, 2014 show a powerful flare of high-energy gamma-radiation from the galaxy IC 310 in the Perseus Cluster, at 260 million light years from earth. This flare was observed with the twin 17-m telescopes of the MAGIC telescope at La Palma/Canary Islands. Ancillary observations with the European VLBI Network - EVN, funded by the EU project RadioNet3, show a remarkable straight plasma jet emerging from the vicinity of a supermassive black hole at the centre of the galaxy, in a region smaller than a light year. Teaming up both instruments, MAGIC and the EVN, provides an unprecedented view of this violent environment of supermassive black holes, the most enigmatic objects in the Universe. Gamma-ray observations have provided the time resolution, and radio interferometric measurements yield a unique imaging capability.

The flickering of the gamma-ray flare on time scales of less than five minutes show that those originated in a region smaller than the event horizon of the black hole. This was a big surprise.

Gamma rays are due to particles accelerated in an extremely narrow region near the black hole permeated by strong electric fields. These structures are expected to form near fast-spinning black holes that power radio jets by their rotational energy loss. Thus, the observations of IC 310 may be the first hint providing direct clues on the enigmatic jet formation process near black holes.

The EVN observations and the post-processing were supported by the transnational access program of the EU FP7 project RadioNet3 (No. 283393).

Image caption: Gamma-ray image of the Perseus cluster (right) with MAGIC, and zooming in a factor of 580000, radio jet image of IC 310 obtained with EVN (left). © Science, AAAS  

More information at:
Science Journal http://www.sciencemag.org/content/early/2014/11/05/science.1256183.full