Evidence for a toroidal magnetic field in the core of 3C 84

Abstract

The spatial scales of relativistic radio jets, probed by relativistic magneto-hydrodynamic jet launching simulations (RMHDs) and by most very-long-baseline interferometry (VLBI) observations differ by an order of magnitude. Bridging the gap between these RMHD simulations and VLBI observations requires selecting nearby active galactic nuclei (AGN), the parsec-scale region of which can be resolved. 3C 84 is a nearby bright AGN fulfilling the necessary requirements: it is launching a powerful, relativistic jet powered by a central supermassive black hole, while also being very bright. Using 22 GHz global VLBI measurements of 3C 84 we aim to study its sub-parsec region in both total intensity and linear polarisation, to explore the properties of this jet, with a linear resolution of $\sim 0.1$ parsec. We test different simulation setups by altering the bulk Lorentz factor $\Gamma$ of the jet, as well as the magnetic field configuration (toroidal, poloidal, helical). We confirm the persistence of a limb brightened structure, which reaches deep into the sub-parsec region. The corresponding electric vector position angles (EVPAs) follow the bulk jet flow inside but tend to be orthogonal to it near the edges. Our state-of-the-art RMHD simulations show that this geometry is consistent with a spine-sheath model, associated with a mildly relativistic flow and a toroidal magnetic field configuration.

10 pages, 8 figures, accepted for publication in Astronomy and Astrophysics

References in corpus (30)

• Array Programming with NumPy
• First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
• First Sagittarius A* Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole in the Center of the Milky Way
• PLUTO: a Numerical Code for Computational Astrophysics
• First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole
• First Sagittarius A* Event Horizon Telescope Results. III: Imaging of the Galactic Center Supermassive Black Hole
• MOJAVE: XV. VLBA 15 GHz Total Intensity and Polarization Maps of 437 Parsec-Scale AGN Jets From 1996-2017
• Kinematics of the jet in M87 on scales of 100 -- 1000 Schwarzschild radii
• A ring-like accretion structure in M87 connecting its black hole and jet
• Polarized Blazar X-rays imply particle acceleration in shocks
• The SFXC software correlator for Very Long Baseline Interferometry: Algorithms and Implementation
• Event Horizon Telescope observations of the jet launching and collimation in Centaurus A
• Kinematics of Parsec-Scale Jets of Gamma-Ray Bright Blazars at 43 GHz during Ten Years of the VLBA-BU-BLAZAR Program
• Magnetic Fields in the Center of the Perseus Cluster
• Discovery of a new subparsec counterjet in NGC 1275: the inclination angle and the environment
• Filamentary structures as the origin of blazar jet radio variability
• X-ray Polarization of BL Lacertae in Outburst
• Probing the Parsec-scale Accretion Flow of 3C 84 with Millimeter Polarimetry
• Magnetic Field Properties inside the Jet of Mrk 421: Multiwavelength Polarimetry Including the Imaging X-ray Polarimetry Explorer
• Evidence of internal rotation and a helical magnetic field in the jet of the quasar NRAO150
• Enhanced Polarized Emission from the One-Parsec-Scale Hotspot of 3C 84 as a Result of the Interaction with Clumpy Ambient Medium
• Polarization calibration techniques for new-generation VLBI
• Pinpointing the jet apex of 3C 84
• Ordered magnetic fields around the 3C 84 central black hole
• A multiband study and exploration of the radio wave - $\gamma$-ray connection in 3C 84
• The long-term centimeter variability of active galactic nuclei: A new relation between variability timescale and accretion rate
• Constraints on Circumnuclear Disk through Free-Free Absorption in the Nucleus of 3C 84 with KaVA and KVN at 43 and 86 GHz
• Observational Evidence to Support a Dense Ambient Medium Shaping the Jet in 3C 84
• Observing the Time Evolution of the Multi-Component Nucleus of 3C\,84
• Closing the feedback-feeding loop of the radio galaxy 3C 84

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