Pinpointing the jet apex of 3C 84

Abstract

Nearby radio galaxies that contain jets are extensively studied with VLBI, addressing jet launching and the physical mechanisms at play around massive black holes. 3C 84 is unique in this regard, because the combination of its proximity and large SMBH mass provides a high spatial resolution to resolve the complex structure at the jet base. For 3C 84 an angular scale of 50 $\mu$as corresponds to 200 - 250 Schwarzschild radii ($R_s$). Recent RadioAstron VLBI imaging at 22 GHz revealed an east-west elongated feature at the northern end of the VLBI jet, which challenges interpretations. Here we propose instead that the jet apex is not located within the 22 GHz VLBI core region but more upstream of the jet. We base our arguments on a 2D cross-correlation analysis of quasi-simultaneously obtained VLBI images at 15, 43, and 86 GHz, which measures the opacity shift of the VLBI core in 3C 84. With the assumption of the power law index ($k_r$) of the core shift being set to 1, we find the jet apex to be located $83\pm 7$ $\mu$as north (upstream) of the 86 GHz VLBI core. Depending on the assumptions for $k_r$ and the particle number density power law index n, we find a mixed toroidal/poloidal magnetic field configuration, consistent with a region which is offset from the central engine by about 400-1500 $R_s$. The measured core shift is then used to estimate the magnetic field strength, which amounts to B = 1.80 - 4.0 G near the 86 GHz VLBI core. We discuss some physical implications of these findings.

arXiv comment8 pages, 4 figures, 5 tables, accepted for publication in Astronomy & Astrophysics Letters

References in corpus (40)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Array Programming with NumPy
• Astropy: A Community Python Package for Astronomy
• Binary companions of evolved stars in APOGEE DR14: Search method and catalog of ~5,000 companions
• Efficient Generation of Jets from Magnetically Arrested Accretion on a Rapidly Spinning Black Hole
• First M87 Event Horizon Telescope Results. II. Array and Instrumentation
• Magnetically Arrested Disk: An Energetically Efficient Accretion Flow
• MOJAVE: Monitoring of Jets in AGN with VLBA Experiments. V. Multi-epoch VLBA Images
• Magnetic field strength and spectral distribution of six parsec-scale active galactic nuclei jets
• Fermi Discovery of Gamma-Ray Emission from NGC 1275
• MOJAVE - XIV. Shapes and opening angles of AGN jets
• The limb-brightened jet of M87 down to 7 Schwarzschild radii scale
• A magnetically collimated jet from an evolved star
• Radiative Processes in High Energy Astrophysics
• VLBA Absorption Imaging of Ionized Gas Associated with the Accretion Disk in NGC 1275
• Magnetohydrodynamic Simulations of Active Galactic Nucleus Disks and Jets
• A wide and collimated radio jet in 3C 84 on the scale of a few hundred gravitational radii
• Limb-Brightened Jet of 3C 84 Revealed by the 43-GHz Very-Long-Baseline-Array Observation
• Magnetic Fields in the Center of the Perseus Cluster
• Kinetic Luminosity and Composition of Active Galactic Nuclei Jets
• Catching the Radio Flare in CTA 102 III. Core-Shift and Spectral Analysis
• Connecting radio variability to the characteristics of gamma-ray blazars
• A Highly Magnetized Twin-Jet Base Pinpoints a Supermassive Black Hole
• Kinematics and Excitation of the Molecular Hydrogen Accretion Disc in NGC 1275
• Relativistic Outflow Drives Gamma-Ray Emission in 3C345
• The core shift effect in the blazar 3C 454.3
• A connection between $\gamma$-ray and parsec-scale radio flares in the blazar 3C 273
• Magnetoluminescence
• Discovery of a new subparsec counterjet in NGC 1275: the inclination angle and the environment
• Gamma-ray flaring activity of NGC 1275 in 2016-2017 measured by MAGIC
• Jet collimation and acceleration in the giant radio galaxy NGC 315
• Spectral distributions in compact radio sources I. Imaging with VLBI data
• Spatially resolved origin of mm-wave linear polarization in the nuclear region of 3C 84
• Observations of CO in the eastern filaments of NGC 1275
• Evidence of internal rotation and a helical magnetic field in the jet of the quasar NRAO150
• VIMAP: an Interactive Program Providing Radio Spectral Index Maps of Active Galactic Nuclei
• Pinpointing the jet apex of 3C 84
• Constraints on Circumnuclear Disk through Free-Free Absorption in the Nucleus of 3C 84 with KaVA and KVN at 43 and 86 GHz
• An Updated Ultraviolet Catalog of GALEX Nearby Galaxies
• Observing the Time Evolution of the Multi-Component Nucleus of 3C\,84

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