Researchers of Aalto University participating in the investigation of the birthplace of γ-ray radiation from quasar 3C279
18.02.2010
An international research group has discovered the birthplace of gamma-ray emission from quasar 3C279.
Researchers from the Metsähovi Radio Observatory participated in this research, in which the Metsähovi radio telescope was utilized. The results of the study titled "A change in the optical polarization associated with a gamma-ray flare in blazar 3C279" appeared in Nature No. 464 on 18th February 2010.
A quasar is a distant active galaxy, where the core is a supermassive black hole. The origins and mechanisms of the variable and relatively strong radiation that quasars produce have long been a mystery to scientists.
Using telescopes with the ability to cover several wavelength ranges, the research group managed to define the source of gamma-ray emission in quasars. These investigations confirmed the earlier theory of researchers at Metsähovi proposing that gamma-ray radiation is generated further from the central black hole than previously believed.
– The Metsähovi Radio Observatory has been following the changes in the radio variability of quasar 3C279, located at a distance of 5 billion light years, for a significant time period. By investigating the connections between radio radiation and gamma-ray radiation in distant galaxies, we have come to understand the behaviour of quasars quite well, explains Professor Merja Tornikoski.
The riddle of the structure of quasars is, however, still not completely solved and these latest results raise further questions.
– In future, we will investigate the structure of quasars' plasma jets and how their magnetic fields maintain the high energies that enable the creation of gamma-ray emission far from the quasar's core, says Tornikoski.
Regular observation of quasars continues at Metsähovi, and the cooperation network also continues to collect more observation data with other telescopes.
– Quasar research can be compared to a jigsaw puzzle. A single observation does not tell us very much, but by combining the results of many telescopes we start to perceive the whole. We are living in the Golden Age of quasar research because we have high quality telescopes and several satellites at our disposal, Academy Research Fellow Anne Lähteenmäki explains.
The research project is led by Researchers Greg Madejski and Masaaki Hayashida at the Kavli Institute at Stanford. The researchers from Aalto University participating in the project are Professor Merja Tornikoski, who is the Director of Metsähovi Radio Observatory, Academy Research Fellow Anne Lähteenmäki and Researcher Talvikki Hovatta from Purdue University in the US.
The research employed NASA's Fermi gamma-ray Space Telescope and more than 20 ground based telescopes.
Web address of the publication:
http://www.nature.com/nature/journal/v463/n7283/full/nature08841.html
More information:
Professor Merja Tornikoski
Metsähovi Radio Observatory
phone: +358 9 428 32048, merja.tornikoski [at] tkk [dot] fi
Academy Research Fellow Anne Lähteenmäki
Metsähovi Radio Observatory
phone: +358 9 428 32047, alien [at] kurp [dot] hut [dot] fi
