%0 Journal Article
%A Peñil Del Campo, Pablo
%A Domínguez, A.
%A Buson, S.
%A Ajello, M.
%A Otero Santos, J.
%A Barrio Uña, Juan Abel
%A Nemmen, R.
%A Cutini, S.
%A Rani, B.
%A Franckowiak, A.
%A Cavazzuti, E.
%T Systematic Search for γ-Ray Periodicity in Active Galactic Nuclei Detected by the Fermi Large Area Telescope
%D 2020
%@ 0004-637X
%U https://hdl.handle.net/20.500.14352/6417
%X We use nine years of gamma-ray data provided by the Fermi Large Area Telescope (LAT) to systematically study the light curves (LCs) of more than 2000 active galactic nuclei (AGN) included in recent Fermi-LAT catalogs. Ten different techniques are used, which are organized in an automatic periodicity-search pipeline, in order to search for evidence of periodic emission in gamma rays. Understanding the processes behind this puzzling phenomenon will provide a better view about the astrophysical nature of these extragalactic sources. However, the observation of temporal patterns in gamma-ray LCs of AGN is still challenging. Despite the fact that there have been efforts to characterize the temporal emission of some individual sources, a systematic search for periodicities by means of a full likelihood analysis applied to large samples of sources was missing. Our analysis finds 11 AGN, of which 9 are identified for the first time, showing periodicity at more than 4 sigma in at least four algorithms. These findings will help in solving questions related to the astrophysical origin of this periodic behavior.
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