Year: 2021
Type: article
Abstract: ABSTRACT On 2019/07/30.86853 ut, IceCube detected a high-energy astrophysical neutrino candidate. The Flat Spectrum Radio Quasar PKS 1502+106 is located within the 50 per cent uncertainty region of the event. Our analysis of 15 GHz Very Long Baseline Array (VLBA) and astrometric 8 GHz VLBA data, in a time span prior and after the IceCube event, reveals evidence for a radio ring structure that develops with time. Several arc-structures evolve perpendicular to the jet ridge line. We find evidence for precession of a curved jet based on kinematic modelling and a periodicity analysis. An outflowing broad line region (BLR) based on the C iv line emission (Sloan Digital Sky Survey) is found. We attribute the atypical ring to an interaction of the precessing jet with the outflowing material. We discuss our findings in the context of a spine-sheath scenario where the ring reveals the sheath and its interaction with the surroundings (narrow line region, NLR, clouds). We find that the radio emission is correlated with the γ-ray emission, with radio lagging the γ-rays. Based on the γ-ray variability time-scale, we constrain the γ-ray emission zone to the BLR (30–200 rg) and within the jet launching region. We discuss that the outflowing BLR provides the external radiation field for γ-ray production via external Compton scattering. The neutrino is most likely produced by proton–proton interaction in the blazar zone (beyond the BLR), enabled by episodic encounters of the jet with dense clouds, i.e. some molecular cloud in the NLR.
Institutions: Max Planck Institute for Radio Astronomy, University of Cologne, Center for Theoretical Physics, Polish Academy of Sciences, University of Belgrade, Astronomical Observatory, Max Planck Institute for Astronomy, University of Geneva, P.N. Lebedev Physical Institute of the Russian Academy of Sciences, Russian Academy of Sciences, Astro Space Center, TU Wien, Chalmers University of Technology, Silesian University in Opava, Goddard Space Flight Center, University of Michigan
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, National Aeronautics and Space Administration, University of Michigan, National Radio Astronomy Observatory, Narodowe Centrum Nauki, Narodowym Centrum Nauki, Ministarstvo Prosvete, Nauke i Tehnološkog Razvoja, Slezská Univerzita v Opavě, Goddard Space Flight Center
Awards: G1566079390, G2295987054, REGENTS OF THE UNIVERSITY OF MICHIGAN LINEAR POLARIZATION AS A PROBE OF THE PHYSICS OF GAMMA-RAY FL, G2694529125, G2875060320, The Radio-Fermi Connection: A Critical Study of Relativistic Jets, G3613655248, WE PROPOSE TO CONTINUE A UMRAO PROGRAM OF MULTIFREQUENCY, CENTIMETER-BAND, LINEAR POLARIZATION AND TOTAL FLUX DENSITY MONITORING OF GAMMA-RAY-BRIGHT, Multi-wavelength Observations of Gamma-Ray Blazars - the GLAST Connection, G475601001, Multifrequency Circular Polarization Spectra as Probes of AGN Jet Physics, THIS PROJECT COMBINES MULTIFREQUENCY, CENTIMETER-BAND, LINEAR POLARIZATION AND TOTAL FLUX DENSITY MONITORING OF GAMMA-RAY-FLARING ACTIVE GALACTIC NUC, G620128262, G670514825, WE PROPOSE TO REVISIT THE IN-SITU HELIOS DATA FOR A MULTI-INSTRUMENT INVESTIGATION OF INNER-HELIOSPHERIC PLASMA HEATING AND THERMALIZATION PROCESSES., G7340048693, ANTHONY REDHEAD/CALIFORNIA INSTITUTE OF TECHNOLOGYMONITORING-1000 GLAST BLAZARS AT 15 GHZ WITH THE O
OpenAlex ID: W3133875495