Searching for Quasiperiodic Modulations in γ-Ray Active Galactic Nuclei

Abstract

Abstract We perform a systematic search of quasiperiodic variabilities in γ-ray active galactic nuclei in the third Fermi Large Area Telescope source catalog (3FGL). We employ two techniques, Lomb–Scargle Periodogram and Weighted Wavelet Z-transform, to obtain power spectra of γ-ray light curves covering from 2008 August to 2016 December. The results show that besides several objects that have been reported in previous works, an additional source, the flat spectrum radio quasars PKS 0601-70 has a possible quasiperiodic variability of 450 days in its γ-ray light curves with the significance of >3σ. The physical implications of our findings are discussed.