Jorstad, Svetlana

The Gamma-ray Activity of the high-Z Quasar 0836+710.

Author list: Svetlana Jorstad, Alan Marscher, Paul Smith, Valeri Larionov, and Ivan Agudo

The Fermi LAT detected an increase in gamma-ray activity of the quasar 0836+710 (z=2.17) in Spring 2011 that culminated in a sharp gamma-ray flare at the end of 2011 when the source reached a flux of 1.4e^-6 phot/s/cm² at 0.1-200 GeV. We monitor the quasar at optical wavelengths in photometric and polarimetric modes and with the VLBA at 43 GHz. The optical brightness of the quasar increased by ~0.5 mag in R-band and the degree of polarization rose by up to 30% during the highest gamma-ray state. We have identified in the VLBA images a strong, highly polarized component that moves with an apparent speed 20+-2 c. The component emerged from the core in the beginning of the gamma-ray event and reached a flux maximum at the peak of the gamma-ray outburst. We present the results of a correlative analysis of variations at different wavelengths along with the kinematic parameters of the parsec scale jet. We discuss the location of the high gamma-ray emission in the relativistic jet, as well as the emission mechanisms responsible for gamma-ray production.

This research was supported in part by NASA grants NNX10AO59G, NNX10AUG15G, aNNX11AQ03G, and NNX12AO90G.