Multimessenger picture of FSRQ J1048+7143

Abstract

In this paper we present the multimessenger picture of the flat-spectrum radio quasar (FSRQ) J1048+7143, a blazar showing gamma-ray quasi-periodic oscillations. We generate the adaptively binned Fermi-LAT light curve of this source above 168 MeV and find three major 𝛾-ray flares, such that each of the flares resolves into two subflares. By analyzing arcsec-scale and milliarcsecscale radio interferometric observations, we find signatures of the precession of a spine-sheath structured jet. We analyze the 5 GHz total flux density curve of J1048+7143 taken with single-dish radio telescopes, and find three complete radio flares that are also suggestive of jet precession. We model the timing of gamma-ray flares as a signature of the spin-orbit precession in a supermassive black hole binary and find that the binary could merge in the next 60-80 yrs.