Radio galaxies from Fermi to the CTA.

We present the results of a study aimed at evaluating the impact of the CTA in high-energy studies of radio galaxies, and elusive class of high-energy and very-high-energy emitters, which counts only 5 detections in the TeV band at the moment. We perform simulations of CTA observations of the Fermi-LAT radio galaxies using the ctools package. Our simulations indicate that 7 out of 12 local (z<0.1) candidates should be detected in 50 hours of CTA integration time, if the Fermi and the CTA powerlaws are smoothly connected. If the spectrum drops off in the TeV band, the number of detections progressively decreases shifting the power-law cut-off to lower energies. Given the elusiveness of radio galaxies at TeV energies, we suggest a CTA observing strategy based on long targeted observations. A blind-sky large area survey implies insufficient integrating time per FoV, but it will be suitable for discovering flaring sources or extremely high-energy peaked radio galaxies that are faint in the Fermi band (and therefore not part of the sample studied here) but observable in the TeV band. Finally we present a diagnostic plot useful to verify whether an AGN with given flux and power-law slope in the Fermi band could be a good target for CTA observations. [ABSTRACT FROM AUTHOR]