Transient quasiperiodic oscillations of Fermi-LAT blazars under the curved jet model

¹ Department of Physics and Astronomy, Clemson University, Kinard Lab of Physics, Clemson SC 29634-0978, USA
² Istituto Nazionale di Fisica Nucleare, Sezione di Padova, 35131 Padova, Italy
³ Julius-Maximilians-Universität Würzburg, Fakultät für Physik und Astronomie, Emil-Fischer-Str. 31, D-97074 Würzburg, Germany
⁴ Deutsches Elektronen-Synchrotron DESY, Platanenallee 6, 15738 Zeuthen, Germany

^⋆ Corresponding authors: ppenil@clemson.edu; jorge.otero@pd.infn.it

Received: 20 May 2025
Accepted: 4 July 2025

Abstract

Context. This study explores transient quasiperiodic oscillations (QPOs) in the γ-ray emission of two blazars, PMN J0531−4827 and PKS 1502+106, using over a decade of Fermi Large Area Telescope observations.

Aims. The analysis focuses on identifying QPO signatures in their long-term light curves and interpreting the variability through a curved jet model, which predicts multiplicative oscillations with exponentially decaying amplitudes.

Methods. We developed an analysis methodology to characterize the QPOs and the specific properties of the amplitudes of such QPOs.

Results. The findings offer insights into the dynamic processes driving relativistic jet evolution and their potential connections to underlying mechanisms, such as binary systems or other phenomena influencing the observed characteristics of these blazars.