Kinematics of the M87 jet in the collimation zone: gradual acceleration and velocity stratification

Abstract

We study the kinematics of the M87 jet using the first year data of the KVN and VERA Array (KaVA) large program, which has densely monitored the jet at 22 and 43 GHz since 2016. We find that the apparent jet speeds generally increase from $\approx 0.3c$ at $\approx 0.5$ mas from the jet base to $\approx 2.7c$ at $\approx 20$ mas, indicating that the jet is accelerated from subluminal to superluminal speeds on these scales. We perform a complementary jet kinematic analysis by using archival Very Long Baseline Array monitoring data observed in $2005-2009$ at 1.7 GHz and find that the jet is moving at relativistic speeds up to $\approx 5.8c$ at distances of $200-410$ mas. We combine the two kinematic results and find that the jet is gradually accelerated over a broad distance range that coincides with the jet collimation zone, implying that conversion of Poynting flux to kinetic energy flux takes place. If the jet emission consists of a single streamline, the observed trend of jet acceleration ($\Gamma \propto z^{0.16\pm 0.01}$) is relatively slow compared to models of a highly magnetized jet. This indicates that Poynting flux conversion through the differential collimation of poloidal magnetic fields may be less efficient than expected. However, we find a non-negligible dispersion in the observed speeds for a given jet distance, making it difficult to describe the jet velocity field with a single power-law acceleration function. We discuss the possibility that the jet emission consists of multiple streamlines following different acceleration profiles, resulting in jet velocity stratification.

arXiv commentAccepted for publication in ApJ; This is a new version after updating Figure 11 in the manuscript

References in corpus (100)

• First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
• First M87 Event Horizon Telescope Results. VI. The Shadow and Mass of the Central Black Hole
• First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole
• First M87 Event Horizon Telescope Results. V. Physical Origin of the Asymmetric Ring
• Efficient Generation of Jets from Magnetically Arrested Accretion on a Rapidly Spinning Black Hole
• First M87 Event Horizon Telescope Results. II. Array and Instrumentation
• First M87 Event Horizon Telescope Results. III. Data Processing and Calibration
• Relativistic Jets in Active Galactic Nuclei
• Magnetically Arrested Disk: An Energetically Efficient Accretion Flow
• Relativistic Reconnection: an Efficient Source of Non-Thermal Particles
• General Relativistic Magnetohydrodynamic Simulations of Jet Formation and Large-Scale Propagation from Black Hole Accretion Systems
• The ACS Fornax Cluster Survey. V. Measurement and Recalibration of Surface Brightness Fluctuations and a Precise Value of the Fornax--Virgo Relative Distance
• Fast TeV variability in blazars: jets in a jet
• The Black-Hole Mass in M87 from Gemini/NIFS Adaptive Optics Observations
• Jet Launching Structure Resolved Near the Supermassive Black Hole in M87
• 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 and Dynamics of the Sub-parsec Scale Jet in M87 Based on 50 VLBA Observations Over 17 Years at 43 GHz
• MOJAVE: Monitoring of Jets in AGN with VLBA Experiments - I. First-Epoch 15 GHz Linear Polarization Images
• The Structure of the M87 Jet: A Transition from Parabolic to Conical Streamlines
• Simulations of Ultrarelativistic Magnetodynamic Jets from Gamma-ray Burst Engines
• Kinematics of the jet in M87 on scales of 100 -- 1000 Schwarzschild radii
• Radio Imaging of the Very-High-Energy Gamma-Ray Emission Region in the Central Engine of a Radio Galaxy
• Numerical Simulation of Hot Accretion Flows (III): Revisiting wind properties using trajectory approach
• MOJAVE XIII. Parsec-Scale AGN Jet Kinematics Analysis Based on 19 years of VLBA Observations at 15 GHz
• Relativistic Magnetohydrodynamics with Application to Gamma-Ray Burst Outflows: I. Theory and Semianalytic Trans-Alfvenic Solutions
• Magnetic Driving of Relativistic Outflows in Active Galactic Nuclei. I. Interpretation of Parsec-Scale Accelerations
• The Inner Jet of the Radio Galaxy M87
• Asymptotic structure of Poynting dominated jets
• MOJAVE - XIV. Shapes and opening angles of AGN 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
• High-Sensitivity 86GHz (3.5mm) VLBI Observations of M87: Deep Imaging of the Jet Base at a 10 Schwarzschild-Radius Resolution
• A Global 86GHz VLBI Survey of Compact Radio Sources
• Dynamics and High Energy Emission of the Flaring HST-1 Knot in the M 87 Jet
• Parabolic Jets from the Spinning Black Hole in M87
• Superluminal Radio Features in the M87 Jet and the Site of Flaring TeV Gamma-ray Emission
• Radiation from the Relativistic Jet: a Role of the Shear Boundary Layer
• High Frequency VLBI Imaging of the Jet Base of M87
• Inside the Bondi radius of M87
• VLBA Absorption Imaging of Ionized Gas Associated with the Accretion Disk in NGC 1275
• Innermost collimation structure of the M87 jet down to ~ten Schwarzschild radii
• 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
• The Optical-Near-IR Spectrum of the M87 Jet From HST Observations
• The Inner Halo of M87: A First Direct View of the Red-Giant Population
• The Parabolic Jet Structure in M87 as a Magnetohydrodynamic Nozzle
• Variability Timescales in the M87 Jet: Signatures of E-Squared Losses, Discovery of a Quasi-period in HST-1, and the Site of TeV Flaring
• Recollimation Shocks in Magnetized Relativistic Jets
• General Relativistic Magnetohydrodynamic Simulations of Blandford-Znajek Jets and the Membrane Paradigm
• Energetics of Tev Blazars and Physical Constraints on their Emission Regions
• Discovery of Sub- to Superluminal Motions in the M87 Jet: An Implication of the Acceleration from Sub-relativistic to Relativistic Speeds
• The Next Generation Virgo Cluster Survey (NGVS). XVIII. Measurement and Calibration of Surface Brightness Fluctuation Distances for Bright Galaxies in Virgo (and Beyond)
• Flaring X-ray Emission from HST-1, a Knot in the M87 Jet
• MOJAVE XII: Acceleration and Collimation of Blazar Jets on Parsec Scales
• The stratified two-sided jet of Cygnus A. Acceleration and collimation
• Recollimation and Radiative Focusing of Relativistic Jets: Applications to Blazars and M87
• Faraday rotation in the jet of M87 inside the Bondi radius: indication of winds from hot accretion flows confining the relativistic jet
• Discovery of a Sub-Parsec Radio Counterjet in the Nucleus of Centaurus A
• Collimation, Acceleration and Recollimation Shock in the Jet of Gamma-Ray-emitting Radio-Loud Narrow-Line Seyfert 1 Galaxy 1H 0323+342
• Magnetization degree at the jet base of M87 derived from the event horizon telescope data: Testing magnetically driven jet paradigm
• Location of Gamma-ray emission and magnetic field strengths in OJ 287
• VLBA Imaging of NGC 4261: Symmetric Parsec-scale Jets and the Inner Accretion Region
• The kinematic of HST-1 in the jet of M87
• Pilot KaVA monitoring on the M87 jet: confirming the inner jet structure and superluminal motions at sub-pc scales
• A connection between $\gamma$-ray and parsec-scale radio flares in the blazar 3C 273
• An Attempt to Probe the Radio Jet Collimation Regions in NGC 4278, NGC 4374 (M84), and NGC 6166
• Spectral evolution of flaring blazars from numerical simulations
• Optical Proper Motion Measurements of the M87 Jet: New Results from the Hubble Space Telescope
• Discovery of a new subparsec counterjet in NGC 1275: the inclination angle and the environment
• Total and linearly polarized synchrotron emission from overpressured magnetized relativistic jets
• Jet launching in resistive GR-MHD black hole - accretion disk systems
• A Magnetohydrodynamic Model of the M87 Jet I: Superluminal Knot Ejections from HST-1 as Trails of Quad Relativistic MHD Shocks
• 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
• On the Magnetic Field in the Kiloparsec-Scale Jet of Radio Galaxy M 87
• Using Twisted Filaments to Model the Inner Jet in M87
• Structural Transition in the NGC 6251 Jet: An Interplay with the Supermassive Black Hole and Its Host Galaxy
• VLBI observations of bright AGN jets with KVN and VERA Array (KaVA): Evaluation of Imaging Capability
• Milli-arcsecond--scale Spectral Properties and Jet Motions in M87
• M87 black hole mass and spin estimate through the position of the jet boundary shape break
• Fast-spinning black holes inferred from symmetrically limb-brightened radio jets
• Capabilities and prospects of the East Asia Very Long Baseline Interferometry Network
• Polarization structure in the core of 1803+784: a signature of recollimation shocks?
• A New Hardware Correlator in Korea: Performance Evaluation using KVN observations
• Relativistic Acceleration of Magnetically Driven Jets
• Resolving the Geometry of the Innermost Relativistic Jets in Active Galactic Nuclei
• Amplitude Correction Factors of KVN Observations
• Revealing the Nature of Blazar Radio Cores through Multi-Frequency Polarization Observations with the Korean VLBI Network
• The TeV-emitting radio galaxy 3C 264. VLBI kinematics and SED modeling
• A Magnetohydrodynamic Model of The M87 Jet. II. Self-consistent Quad-shock Jet Model for Optical Relativistic Motions and Particle Acceleration
• Reconfinement of highly magnetized jets: Implications for HST-1 in M87
• Jet Kinematics of the Quasar 4C +21.35 from Observations with the KaVA Very Long Baseline Interferometry Array
• Detection of multiple velocity components in partially overlapping emitting regions
• A comparative study of amplitude calibrations for East-Asia VLBI Network: a-priori and template spectrum methods
• PAGaN II: The Evolution of AGN Jets on Sub-Parsec Scales
• A sensitive study of the peculiar jet structure HST-1 in M87

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• Linear polarization in the nucleus of M87 at 7 mm and 1.3 cm
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• A unified model for orphan and multi-wavelength blazar flares
• Broadband Multi-wavelength Properties of M87 during the 2018 EHT Campaign including a Very High Energy Flaring Episode
• Deciphering the Origin of the GeV--TeV Gamma-ray Emission from SS 433
• The intrinsic structure of Sagittarius A* at 1.3 cm and 7 mm
• Spectral analysis of a parsec-scale jet in M87: Observational constraint on the magnetic field strengths in the jet
• M87: a cosmic laboratory for deciphering black hole accretion and jet formation
• Magnetic Reconnection in Black-Hole Magnetospheres: Lepton Loading into Jets, Superluminal Radio Blobs, and Multi-wavelength Flares
• Implications from the velocity profile of the M87 jet: a possibility of a slowly rotating black hole magnetosphere
• East Asian VLBI Network Observations of Active Galactic Nuclei Jets: Imaging with KaVA+Tianma+Nanshan
• Dual-high-frequency VLBI study of blazar-jet brightness-temperature gradients and collimation profiles
• A detailed kinematic study of 3C 84 and its connection to Gamma-rays
• The Origin of Matter at the Base of Relativistic Jets in Active Galactic Nuclei
• Signatures of Black Hole Spin and Plasma Acceleration in Jet Polarimetry
• 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
• The content of astrophysical jets
• Interface instabilities in hydrodynamic relativistic jets
• Overview of the Observing System and Initial Scientific Accomplishments of the East Asian VLBI Network (EAVN)
• Transverse Oscillations of the M87 Jet Revealed by KaVA Observations
• Hybrid GRMHD and Force-Free Simulations of Black Hole Accretion
• Observational Evidence to Support a Dense Ambient Medium Shaping the Jet in 3C 84
• Polarization Observations of AGN Jets: Past and Future
• Numerical simulations of MHD jets from Keplerian accretion disks I-Recollimation shocks
• Active galactic nuclei jets simulated with smoothed particle hydrodynamics
• Interferometric Monitoring of Gamma-ray Bright AGNs: Measuring the Magnetic Field Strength of 4C +29.45
• Toward a Full MHD Jet Model of Spinning Black Holes--II: Kinematics and Application to the M87 Jet
• Jet Collimation and Acceleration in the Flat Spectrum Radio Quasar 1928+738
• Blob formation and ejection from the radiative inefficient accretion flow around massive black hole
• The optimization of satellite orbit for Space-VLBI observation
• On the Internal Structure of Relativistic Jets with Zero Velocity Along the Axis
• Matter density distribution of general relativistic highly magnetized jets driven by black holes
• Relativistic AGN jets III. Synthesis of synchrotron emission from Double-Double Radio Galaxies
• Relativistic jet acceleration region in a black hole magnetosphere
• Super-Resolved Image of M87 Observed with East Asian VLBI Network
• Kilogauss magnetic field and jet dynamics in the quasar NRAO 530
• Analysis of Jet Dynamics and Collimation Characteristics of 0241+622 on Parsec Scales
• Transverse Oscillations and Wave Propagation in the Magnetically Dominated M87 Jet
• Investigating the Disk-Jet Structure in M87 through Flux Separation in the Linear and Circular Polarization Images
• Apparent superluminal velocities and random walk in the velocity space
• Nonuniform Particle Injection into Black Hole Jets by Radiative Magnetic Reconnection
• A revised view of the linear polarization in the subparsec core of M87 at 7 mm