Speaker
Dr
Michael Zacharias
(North-West University)
Description
A key project of the High Energy Stereoscopic System (H.E.S.S.) is the regular monitoring of different types of blazars at very high energies (E>100 GeV). Since the inauguration of H.E.S.S. in 2004 the high-frequency peaked BL Lac object PKS 2155-304 and the radio galaxy M 87 have been observed frequently. The flat spectrum radio quasar PKS 1510-089 has been added to the list of monitored sources after its detection during a flare in 2009. In this talk, recent results of these monitoring efforts will be presented, including evidence that the quiescent and flaring states differ in more than merely flux levels in PKS 2155-304. This points to different processes producing these states. Monitoring with H.E.S.S. phase II of PKS 1510-089 in 2015 revealed for the first time VHE night-by-night variability in this source, implying that the flaring region must be located on the edge or beyond the broad line region.
Primary author
Dr
Michael Zacharias
(North-West University)
Co-author
H.E.S.S. Collaboration
(H.E.S.S. collaboration)
