Revisiting the quasi-periodic oscillations in blazar PG 1553＋113 with multi-wavebands data

Abstract

The blazar PG 1553＋113 is hypothesized to harbor a supermassive black hole binary system, a scenario that aligns with its observed physical characteristics. In this study, we re-examine the authenticity of the periodicity of PG 1553＋113 by conducting a comprehensive analysis of multi-wavebands periodic light variations, using the updated light curve data of more than 15 years. We used two methods to search for the light curves data of this blazar in γ-ray, X-ray, optical and radio bands. The multi-wavebands analysis approach enables a thorough verification of the observed periodic patterns. The result of γ-ray detection showed a quasi-periodic oscillation (QPO) of 2.16 years, which verified the results given by Ackermann et al. (2015). And the optical band shows a QPO of 2.24 years. We analyzed the correlation among γ-ray, optical and radio bands, and we found that there is a strong correlation among them, and the emission of different bands coming from the same region (the same electron group). Finally, we estimated the black hole mass of PG 1553＋113 to be M≃4.3×109M⨀ based on the binary black hole model.