http://arxiv.org/abs/2009.13754
We report the detection of a probable $\gamma$-ray quasi-periodic oscillation (QPO) of around 314 days in the monthly binned 0.1 — 300 GeV $\gamma$-ray {\it Fermi}-LAT light curve of the well known BL Lac blazar OJ 287. To identify and quantify the QPO nature of the $\gamma$-ray light curve of OJ 287, we used the Lomb-Scargle periodogram (LSP), REDFIT, and weighted wavelet z-transform (WWZ) analyses. We briefly discuss possible emission models for radio-loud active galactic nuclei (AGN) that can explain a $\gamma$-ray QPO of such a period in a blazar. Reports of changes in the position of quasi-stationary radio knots over a yearly timescale as well as a strong correlation between gamma-ray and mm-radio emission in previous studies indicate that the signal is probably associated with these knots.
P. Kushwaha, A. Sarkar, A. Gupta, et. al.
Wed, 30 Sep 2020
52/86
Comments: 6 pages, 4 figures, in press (MNRAS)