Astronomy and Astrophysics – Astrophysics – High Energy Astrophysical Phenomena
Scientific paper
2012-02-09
Astronomy and Astrophysics
Astrophysics
High Energy Astrophysical Phenomena
14 pages, 1 figure, submitted to MNRAS
Scientific paper
We study theoretical implications of a rapid Very-High-Energy (VHE) flare detected by MAGIC in the Flat-Spectrum Radio Quasar PKS 1222+216. The minimum distance from the jet origin at which this flare could be produced is 0.5 pc. A moderate Doppler factor of the VHE source, D_{VHE}~20, is allowed by all opacity constraints. The concurrent High-Energy (HE) emission observed by Fermi provides estimates of the total jet power and the jet magnetic field strength. Energetic constraints for the VHE flare are extremely tight, requiring a very high co-moving energy density in the emitting region and a very efficient radiative process. We disfavor hadronic processes due to their low radiative efficiency. The External Radiation Compton (ERC) mechanism involving the infrared radiation of the dusty torus is efficient for D_{VHE}>~50. For a magnetic field strength >~0.03 G x (D_{VHE}/20)^5, the Synchrotron Self-Compton (SSC) process dominates the ERC. We consider a scenario involving synchrotron emission by ultra-relativistic electrons accelerated in a magnetic reconnection layer, as has been recently proposed for the case of HE flares in the Crab Nebula. For the case of PKS 1222+216, this mechanism requires an effective electric-to-magnetic field ratio within the layer of ~26 x (D_{VHE}/20)^{-1}, and a reconnecting magnetic field strength of ~130 G x (D_{VHE}/20)^{-3}. For the origin of an extremely compact emitting region, we prefer a self-collimated jet substructure maintaining its original energy density during propagation to parsec scales, over global jet recollimation by the external medium.
Begelman Mitchell C.
Cerutti Benoit
Nalewajko Krzysztof
Sikora Marek
Uzdensky Dmitri A.
No associations
LandOfFree
Energetic Constraints on a Rapid Gamma-Ray Flare in PKS 1222+216 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Energetic Constraints on a Rapid Gamma-Ray Flare in PKS 1222+216, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Energetic Constraints on a Rapid Gamma-Ray Flare in PKS 1222+216 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-273657