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arXiv · 1512.08801

Gamma-ray and optical oscillations in the blazar PKS 0537-441

Angela Sandrinelli·Stefano Covino·Aldo Treves
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Abstract

We have considered the \textit{Fermi} $γ$-ray light curve of the blazar PKS 0537-441 during a high state extending from 2008/08/10 to 2011/08/27. The periodogram exhibits a peak at T $\sim$ 280 d, with a significance of $\sim$ 99.7 \%. A peak of similar relevance at $\frac{1}{2}$ T is found in the optical light curves. Considering the entire duration of the \textit{ Fermi} light curve 2008-2015, no significant peak is revealed, while the optical one remains meaningful. Comparing with recent observations of PKS 2155-304 and PG 1553+113 it seems that month-year oscillations can characterize some blazars. Month-scale oscillations can also show up only during phases of enhanced or bursting emission like in the case of PKS 0537-441.

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Angela Sandrinelli, Stefano Covino, Aldo Treves. 2015-12-29. Gamma-ray and optical oscillations in the blazar PKS 0537-441. https://doi.org/10.3847/0004-637x%2F820%2F1%2F20

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