2011/11/28 by Amanda Dotson, Dotson, Amanda, Markos Georganopoulos +6
Engineering · Physics and Astronomy · #Astrophysics and Cosmic Phenomena #FOS: Physical sciences #Gyrotron and Vacuum Electronics Research #High Energy Astrophysical Phenomena (astro-ph.HE) #Particle Accelerators and Free-Electron Lasers #astro-ph.HE
paper · pdf · doi:10.48550/arxiv.1111.6551
2011 Fermi Symposium proceedings - eConf C110509
arxiv created 2011/11/28 · openalex publication_date 2011/11/28 · arxiv updated 2011/11/29 · openalex created_date 2022/10/02 · openalex updated_date 2026/07/28
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 clear 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 few 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.