Very high energy γ-radiation from the radio quasar 4C 21.35

González, Josefa Becerra; Maraschi, Laura; Mazin, Daniel; Prandini, Elisa; Saito, Koji; Sitarek, Julian; Stamerra, Antonio; Tavecchio, Fabrizio; Terzić, Tomislav; Treves, Aldo; aff0011
Bibliographical reference

The Spectral Energy Distribution of Galaxies, Proceedings of the International Astronomical Union, IAU Symposium, Volume 284, p. 414-416

Advertised on:
8
2012
Number of authors
11
IAC number of authors
1
Citations
0
Refereed citations
0
Description
A very high energy (VHE) γ-radiation was detected from a flat spectrum radio quasar (FSRQ) 4C 21.35 (PKS1222+21) by MAGIC (Major Atmospheric Gamma Imaging Cherenkov) telescopes on June 17 th 2010. 4C 21.35 is only the 3 rd FSRQ detected in VHE γ-rays. With its hard spectrum (Γ = 2.72+/-0.34) with no apparent cut-off at energies below 130 GeV and an extremely fast variation of flux (doubling in 8.6+1.1 -0.9 minutes), this detection poses a challenge to existing models of VHE γ-radiation from FSRQs. The most important results of observations performed by MAGIC telescopes are presented here, as well as some possible explanations of those results.