Tuesday, June 5, 2012

1206.0012 (Amanda Dotson et al.)

Determining the location of the GeV emission in powerful blazars    [PDF]

Amanda Dotson, Markos Georganopoulos, Demosthenes Kazanas, Eric Perlman
An issue currently under debate in the literature is how far from the black hole is the Fermi-observed GeV emission of powerful blazars emitted. Here we present a diagnostic tool for testing whether the GeV emission site is located within the sub-pc broad emission line (BLR) region or further out in the pc scale molecular torus (MT) environment. Within the BLR the scattering takes place at the onset of the Klein-Nishina regime, causing the electron cooling time to become almost energy independent and as a result, the variation of high-energy emission is expected to be achromatic. Contrarily, if the emission site is located outside the BLR, the expected GeV variability is energy-dependent and with amplitude increasing with energy. We demonstrate this using time-dependent numerical simulations of blazar variability and discuss the applicability of our method.
View original: http://arxiv.org/abs/1206.0012

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