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arXiv · 1810.12607

Detection of a quasi-periodic oscillation in gamma-ray light curve of the high redshift blazar B2 1520+31

Alok C. Gupta·Ashutosh Tripathi·Paul J. Wiita·Pankaj Kushwaha·Zhongli Zhang·Cosimo Bambi
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Abstract

We detected a possible quasi-periodic oscillation (QPO) of ~ 71 days in the 0.1 -- 300 GeV gamma-ray Fermi-LAT light curve of the high redshift flat spectrum radio quasar B2 1520+31. We identify and confirm that quasi-period by Lomb Scargle periodogram (LSP), and weighted wavelet z-transform (WWZ) analyses. Using this QPO period, and assuming it originates from accretion-disc fluctuations at the innermost stable circular orbit, we estimate the central supermassive black hole mass to range between ~ 5.4 * 10$^{9}$ M$_{\odot}$ for a non-rotating black hole and ~ 6.0 * 10$^{10}$ M$_{\odot}$ for a maximally rotating black hole. We briefly discuss other possible radio-loud active galactic nuclei emission models capable of producing a gamma-ray QPO of such a period in a blazar.

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Alok C. Gupta, Ashutosh Tripathi, Paul J. Wiita, Pankaj Kushwaha, Zhongli Zhang, Cosimo Bambi. 2018-10-30. Detection of a quasi-periodic oscillation in gamma-ray light curve of the high redshift blazar B2 1520+31. https://doi.org/10.1093/mnras%2Fstz395

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