Tuorla Observatory News 18 April 2013

Brightest ever observed gamma-ray flare from blazar Markarian 421

In the past days the skies have been flooded with the brightest display of Very High Energy gamma rays - the Universe's highest-energy light - ever seen by astronomers. The gamma-rays originate from blazar Markarian 421, located 0.4 billion light years away. Blazars are active galactic nuclei, galaxies hosting supermassive black holes in their centre. The supermassive black hole launches relativistic jet. In the case of blazars this jet is oriented close to our line of sight and the emission is boosted by the relativistic effects. Blazars are extremely bright in all energy regimes from radio to very high energy gamma-rays. The very high energy gamma-rays were observed by the MAGIC telescopes located in Canary Island of La Palma. The telescopes are operated by large international collaboration including researchers from Tuorla Observatory and Finnish Centre for Astronomy with ESO (Elina Lindfors, Kari Nilsson, Riho Reinthal, Aimo Sillänpää and Leo Takalo). The extraordinary flaring event is currently followed by all blazar researchers. Riho Reinthal, PhD student in Tuorla Observatory, has been following the source closely with the optical KVA telescope at La Palma, and the observations show that the source has also reached historical high state in optical. The observations with X-ray satellites have also shown extraordinary brightening. The historical high state has also get attention in the media and was reported in the BBC news (http://www.bbc.co.uk/news/science-environment-22162806). The observations will continue to unveil what caused this spectacular event.

This page was last modified by  Pasi Nurmi  on  18/04/2013  pasnurmi@utu.fi