AGN Forecasting

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Citation of Original Publication

T. Hassan, N. Mirabal and J.L. Contreras, AGN Forecasting, AGN Physics in the CTA Era (AGN 2011) - Session 3 : AGN population studies and expected CTA performances, Volume 141, DOI:


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The First Fermi-LAT catalog (1FGL) represents the most complete list of sources in the GeV sky to date. We use the reported 1FGL spectral parameters to extrapolate Fermi AGN spectra to the very-high energy (VHE) range (15 GeV – 300 TeV). The extrapolated VHE spectra are then attenuated using current estimations of the extragalactic background light (EBL) absorption as a function of redshift. Using the expected effective areas and background rates of the Cherenkov Telescope Array (CTA) from Monte Carlo simulations, we make a first order prediction of the AGN population accessible to CTA in the VHE sky. We find that CTA should easily triple the AGN detection rate of current ground-based Cherenkov telescopes. In addition, CTA should allow unprecedented access to high-redshift blazars out to z ≈ 2, and hence will start to reveal the EBL shape with gamma-ray observations.