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arXiv · 1701.00899

Possible Quasi-Periodic modulation in the z = 1.1 $γ$-ray blazar PKS 0426-380

Pengfei Zhang·Dahai Yan·Nenghui Liao·Wei Zeng·Jiancheng Wang·Lijia Cao
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Abstract

We search for $γ$-ray and optical periodic modulations in a distant flat spectrum radio quasar (FSRQ) PKS 0426-380 (the redshift $z=1.1$). Using two techniques (i.e., the maximum likelihood optimization and the exposure-weighted aperture photometry), we obtain $γ$-ray light curves from \emph{Fermi}-LAT Pass 8 data covering from 2008 August to 2016 December. We then analyze the light curves with the Lomb-Scargle Periodogram (LSP) and the Weighted Wavelet Z-transform (WWZ). A $γ$-ray quasi-periodicity with a period of 3.35 $\pm$ 0.68 years is found at the significance-level of $\simeq3.6\ σ$. The optical-UV flux covering from 2005 August to 2013 April provided by ASI SCIENCE DATA CENTER is also analyzed, but no significant quasi-periodicity is found. It should be pointed out that the result of the optical-UV data could be tentative because of the incomplete of the data. Further long-term multiwavelength monitoring of this FSRQ is needed to confirm its quasi-periodicity.

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Pengfei Zhang, Dahai Yan, Nenghui Liao, Wei Zeng, Jiancheng Wang, Lijia Cao. 2017-05-17. Possible Quasi-Periodic modulation in the z = 1.1 $γ$-ray blazar PKS 0426-380. https://doi.org/10.3847/1538-4357%2Faa7465

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