Prof Esko Valtoja (Tuorla Observatory, University of Turku)

ORIGIN OF HIGH FREQUENCY RADIATION IN ACTIVE GALACTIC NUCLEI - Prof Esko Valtoja Colloquium

ATNF Marsfield Lecture Theatre

Abstract

The discovery of strong gamma-ray emission from AGN, made by the COMPTON
satellite in 1991, surprised researchers - although, with hindsight, the
discovery was to be expected on theoretical grounds. A decade later there
is a consensus that the high frequency emission, from X-rays to TeV
range, is inverse Compton radiation from relativistic electrons in the
synchrotron-emitting AGN jets. The seed photons come either from the
accretion disk or from the broad line region, and the high frequency
radiation originates close to the central black hole. Always happy to
disagree, I will present new evidence that this consensus may be rather
premature.