Quasi-periodic behaviour in the radio and γ-ray light curves of blazar PKS 1510-089
Abstract
We explore the possible quasi-periodic oscillations (QPOs) of the blazar PKS 1510-089, utilizing the ~38-yr Metsähovi flux density observations at 37 GHz and over 10-yr Fermi Large Area Telescope observations in the 0.1-300 GeV energy range. Both the flux distributions of the radio and γ-ray light curves suggest a lognormal distribution, and power spectral densities of both light curves can be well represented by a bending power-law model. Comparing the results from the weighted wavelet Z-transform and Lomb-Scargle periodogram approaches, a quasi-period of 1330 ± 55 d at a 99.80 per cent (>3σ) significance against the red noise background is observed in the radio light curve, whereas no similar modulation is seen in the γ-ray light curve. We briefly discuss the research actuality of blazar QPO phenomena and explain the observed radio QPO as the result of Keplerian motion in a supermassive binary black hole system and periodic modulation induced by the Lense-Thirring precession of the innermost portions of the accretion disc.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- January 2023
- DOI:
- 10.1093/mnras/stad008
- Bibcode:
- 2023MNRAS.519.4893L
- Keywords:
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- galaxies: active;
- BL Lacertae objects: general;
- BL Lacertae objects: individual: PKS 1510-089