Abstract

Contributed Talk - Splinter AGN   (MW-1250)

Lepto-Hadronic Modelling of Multi-Messenger Emission from Precessing Blazar Jets

Simon Porten, Vladimir Kiselev, Ilja Jaroschewski, Julia Tjus
Ruhr Universität Bochum, Ruhr Universität Bochum, Université Paris-Saclay, Ruhr Universität Bochum

Quasi-periodic Oscillations (QPOs) in active galactic nuclei (AGN), especially blazars, have been observed on timescales from hours to years. By now, several blazars are known to exhibit year-scale QPOs, often in their gamma-ray light curves. Different explanations for this behaviour have been proposed, some of which involve a binary system of supermassive black holes (SMBBH). In such a system, the spin axes of the black holes undergo precession due to spin-orbit coupling, which may lead to the precession of the jet(s) of the AGN. The varying angle to the line-of-sight then leads to a change in Doppler factor and thus the observed brightness of the source. PG 1553+113 is a blazar that has been proposed as a candidate SMBBH system, exhibiting QPOs with a period of roughly two years across multiple bands, most notably the Fermi-LAT gamma-ray light curve. In this talk I will present the results of my master's thesis on the modelling of multi-messenger emission from such a system of SMBBH. I use PG 1553+113 as a case study, combining a lepto-hadronic model with jet-precession to model the multi-wavelength light curves of the source as well as potential neutrino emission.