Observational Evidence to Support a Dense Ambient Medium Shaping the Jet in 3C 84

Abstract

Highly collimated relativistic jets are a defining feature of certain active galactic nuclei (AGN), yet their formation mechanism remains elusive. Previous observations and theoretical models have proposed that the ambient medium surrounding the jets could exert pressure, playing a crucial role in shaping the jets. However, direct observational confirmation of such a medium has been lacking. In this study, we present very long baseline interferometric (VLBI) observations of 3C 84 (NGC 1275), located at the center of the Perseus Cluster. Through monitoring observations with the Very Long Baseline Array (VLBA) at 43 GHz, a jet knot was detected to have been ejected from the sub-parsec scale core in the late 2010s. Intriguingly, this knot propagated in a direction significantly offset from the parsec-scale jet direction. To delve deeper into the matter, we employ follow-up VLBA 43 GHz observations, tracing the knot's trajectory until the end of 2022. We discovered that the knot abruptly changed its trajectory in the early 2020s, realigning itself with the parsec-scale jet direction. Additionally, we present results from an observation of 3C 84 with the Global VLBI Alliance (GVA) at 22 GHz, conducted near the monitoring period. By jointly analyzing the GVA 22 GHz image with a VLBA 43 GHz image observed about one week apart, we generated a spectral index map, revealing an inverted spectrum region near the edge of the jet where the knot experienced deflection. These findings suggest the presence of a dense, cold ambient medium characterized by an electron density exceeding $\sim 10^5\mathrm{c}{\mathrm{m}}^{-3}$, which guides the jet's propagation on parsec scales and significantly contributes to the overall shaping of the jet.

arXiv comment18 pages, 18 figures, accepted for publication in Astronomy and Astrophysics

References in corpus (75)

• Coevolution (Or Not) of Supermassive Black Holes and Host Galaxies
• Observational Evidence of AGN Feedback
• First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole
• Hot Accretion Flows Around Black Holes
• Relativistic Jets in Active Galactic Nuclei
• General Relativistic Magnetohydrodynamic Simulations of Jet Formation and Large-Scale Propagation from Black Hole Accretion Systems
• Fast TeV variability in blazars: jets in a jet
• Chaotic cold accretion onto black holes
• The 1% Concordance Hubble Constant
• Magnetic acceleration of ultra-relativistic jets in gamma-ray burst sources
• Magnetic acceleration of relativistic AGN jets
• Kinematics of Parsec-Scale Jets of Gamma-Ray Blazars at 43~GHz within the VLBA-BU-BLAZAR Program
• The Structure of the M87 Jet: A Transition from Parabolic to Conical Streamlines
• 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
• Numerical Simulation of Hot Accretion Flows (III): Revisiting wind properties using trajectory approach
• Reconnection-driven plasmoids in blazars: fast flares on a slow envelope
• Fermi Discovery of Gamma-Ray Emission from NGC 1275
• Asymptotic structure of Poynting dominated jets
• Rapid Variability of Blazar 3C 279 during Flaring States in 2013-2014 with Joint Fermi-LAT, NuSTAR, Swift, and Ground-Based Multi-wavelength Observations
• Energy, momentum and mass outflows and feedback from thick accretion discs around rotating black holes
• The limb-brightened jet of M87 down to 7 Schwarzschild radii scale
• Optical and Radio Polarimetry of the M87 Jet at 0.2" Resolution
• Radiation-driven Fountain and Origin of Torus around Active Galactic Nuclei
• Parabolic Jets from the Spinning Black Hole in M87
• VLBA Absorption Imaging of Ionized Gas Associated with the Accretion Disk in NGC 1275
• MOJAVE: Monitoring of Jets in Active Galactic Nuclei with VLBA Experiments. XI. Spectral distributions
• Accelerating AGN jets to parsec scales using general relativistic MHD simulations
• A wide and collimated radio jet in 3C 84 on the scale of a few hundred gravitational radii
• Kinematics of Parsec-Scale Jets of Gamma-Ray Bright Blazars at 43 GHz during Ten Years of the VLBA-BU-BLAZAR Program
• Spectral evolution of superluminal components in parsec-scale jets
• Limb-Brightened Jet of 3C 84 Revealed by the 43-GHz Very-Long-Baseline-Array Observation
• A transition from parabolic to conical shape as a common effect in nearby AGN jets
• The Parabolic Jet Structure in M87 as a Magnetohydrodynamic Nozzle
• Catching the Radio Flare in CTA 102 III. Core-Shift and Spectral Analysis
• Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign
• Energetics of Tev Blazars and Physical Constraints on their Emission Regions
• The stratified two-sided jet of Cygnus A. Acceleration and collimation
• Faraday rotation in the jet of M87 inside the Bondi radius: indication of winds from hot accretion flows confining the relativistic jet
• Collimation, Acceleration and Recollimation Shock in the Jet of Gamma-Ray-emitting Radio-Loud Narrow-Line Seyfert 1 Galaxy 1H 0323+342
• VLBI Monitoring of 3C 84 (NGC 1275) in Early Phase of the 2005 Outburst
• Aligning VLBI Images of Active Galactic Nuclei at Different Frequencies
• Kinematics of the M87 jet in the collimation zone: gradual acceleration and velocity stratification
• Jet collimation in NGC 315 and other nearby AGN
• Magnetization degree at the jet base of M87 derived from the event horizon telescope data: Testing magnetically driven jet paradigm
• A spinning supermassive black hole binary model consistent with VLBI observations of the S5 1928+738 jet
• The ALMA Discovery of the Rotating Disk and Fast Outflow of Cold Molecular Gas in NGC 1275
• On the spine-layer scenario for the very high-energy emission of NGC 1275
• A connection between $\gamma$-ray and parsec-scale radio flares in the blazar 3C 273
• Contemporaneous observations of the radio galaxy NGC 1275 from radio to very high energy gamma-rays
• Discovery of a new subparsec counterjet in NGC 1275: the inclination angle and the environment
• Jet collimation and acceleration in the giant radio galaxy NGC 315
• Monitoring of the radio galaxy M87 during a low emission state from 2012 to 2015 with MAGIC
• Relativistic electrons and magnetic field of the M87 jet on ~ten Schwarzschild radii scale
• Wavelet-based decomposition and analysis of structural patterns in astronomical images
• Probing the Parsec-scale Accretion Flow of 3C 84 with Millimeter Polarimetry
• Structural Transition in the NGC 6251 Jet: An Interplay with the Supermassive Black Hole and Its Host Galaxy
• Probing the innermost regions of AGN jets and their magnetic fields with RadioAstron II. Observations of 3C 273 at minimum activity
• KVN observations suggest multiple $\gamma$-ray emission regions in 3C 84
• Evidence for nuclear radio jet and its structure down to <100 Schwarzschild radii in the center of the Sombrero galaxy (M 104, NGC 4594)
• Collimation of the relativistic jet in the quasar 3C 273
• VIMAP: an Interactive Program Providing Radio Spectral Index Maps of Active Galactic Nuclei
• Pinpointing the jet apex of 3C 84
• Evidence of jet-clump interaction: a flip of the radio jet head of 3C~84
• A multiband study and exploration of the radio wave - $\gamma$-ray connection in 3C 84
• GPCAL: a generalized calibration pipeline for instrumental polarization in VLBI data
• RadioAstron discovery of a mini-cocoon around the restarted parsec-scale jet in 3C 84
• RadioAstron Space VLBI Imaging of the jet in M87: I. Detection of high brightness temperature at 22 GHz
• Maximum Brightness Temperature of an Incoherent Synchrotron Source : Inverse Compton Limit - a Misnomer
• Jet kinematics in the transversely stratified jet of 3C 84 A two-decade overview
• Multiband RadioAstron space VLBI imaging of the jet in quasar S5 0836+710
• Constraints on Circumnuclear Disk through Free-Free Absorption in the Nucleus of 3C 84 with KaVA and KVN at 43 and 86 GHz
• A detailed kinematic study of 3C 84 and its connection to Gamma-rays
• Overview of the Observing System and Initial Scientific Accomplishments of the East Asian VLBI Network (EAVN)
• Observing the Time Evolution of the Multi-Component Nucleus of 3C\,84

Cited by in corpus (4)

• Discovery of Limb Brightening in the Parsec-scale Jet of NGC 315 through Global Very Long Baseline Interferometry Observations and Its Implications for Jet Models
• Evidence for a toroidal magnetic field in the core of 3C 84
• Evolution, speed, and precession of the parsec-scale jet in the 3C 84 radio galaxy
• Where within the 3C 84 jet are $\gamma$-rays produced?