Gamma-ray emission from supermassive black hole binary OJ 287

Vera Yu Sinitsyna,Vera G Sinitsyna,W Liu,S Zeng,Y Wang,X Tang,B Guo

doi:10.1051/epjconf/202226011047

Abstract

OJ 287 is one of the most studied BL Lacs with very long optical measurements which spectrum has been well measured through radio to X-rays. OJ 287 is supposed to be a binary black hole system. Its secondary black hole passes the accretion disk of the primary black hole and produces two impact flashes per 12-year period. Observations of OJ 287 in the GeV – TeV energy range reveal the variable γ-ray flux connected with the flare activity of this object. The spectral energy distributions of BL Lac objects consist of two broad peaks. The Inverse Compton emission of the relativistic electrons in the jet or combined with an external Compton mechanism are considered in the leptonic scenario of second, higher frequency spectrum part generation. The last one supposes the existence of the external to jet photon cloud. Also, the second spectrum part is supposed to be generated due to the acceleration of the cosmic ray hadrons in expanding shock produced by outflow, which then collides with the wind of the primary black hole. The detection of GeV – TeV energy fluxes can help find the configuration parameters of the two-black hole system.

Highlights

BL Lacs are a high and rapidly variable subclass of radio-loud, active galactic nuclei (AGN) characterized by non-thermal spectra extending from radio to high and very high energy γrays
The spectral energy distribution of the BL Lacs is of a two-hump shape with a first peaking at a low-energy in infrared to X-ray range and a second at high energy γ-rays
The cosmic ray proton acceleration occurs in the shock generated by outflows interactions with the active galactic nucleus wind of the heavier black hole

Summary

Introduction

BL Lacs are a high and rapidly variable subclass of radio-loud, active galactic nuclei (AGN) characterized by non-thermal spectra extending from radio to high and very high energy γrays. The short time variability of a day or even minute timescale and the detection at TeV energies points to the origin of emission from the relativistic jets directed to the observer sightline [1]. It suggests that the emission region is located at the parsec scales from the central powering engine. The spectral energy distribution of the BL Lacs is of a two-hump shape with a first peaking at a low-energy in infrared to X-ray range and a second at high energy γ-rays The production of these emission components and their connection is widely studied. The observations of powerful BL Lac-type active galactic nuclei can provide information for the models of described the jet dynamic in AGNi and their emission in the wide range of the electromagnetic spectrum

OJ 287

Discussion

Conclusions