Blazar duty-cycle at γ-ray frequencies: constraints from extragalactic background radiation and prospects for AGILE and GLAST

Abstract We take into account the constraints from the observed extragalactic γ-ray background to estimate the maximum duty cycle allowed for a selected sample of WMAP Blazars, in order to be detectable by AGILE and GLAST γ-ray experiments. For the nominal sensitivity values of both instruments, we identify a subset of sources which can in principle be detectable also in a steady state without over-predicting the extragalactic background. This work is based on the results of a recently derived Blazar radio LogN-LogS obtained by combining several multi-frequency surveys.