A multi-frequency study of sub-parsec jets with the Event Horizon Telescope

Abstract

The 2017 observing campaign of the Event Horizon Telescope (EHT) delivered the first very long baseline interferometry (VLBI) images at the observing frequency of 230 GHz, leading to a number of unique studies on black holes and relativistic jets from active galactic nuclei (AGN). In total, eighteen sources were observed: the main science targets, Sgr A* and M87 along with various calibrators. We investigated the morphology of the sixteen AGN in the EHT 2017 data set, focusing on the properties of the VLBI cores: size, flux density, and brightness temperature. We studied their dependence on the observing frequency in order to compare it with the Blandford-Königl (BK) jet model. We modeled the source structure of seven AGN in the EHT 2017 data set using linearly polarized circular Gaussian components and collected results for the other nine AGN from dedicated EHT publications, complemented by lower frequency data in the 2-86 GHz range. Then, we studied the dependences of the VLBI core flux density, size, and brightness temperature on the frequency measured in the AGN host frame. We compared the observations with the BK jet model and estimated the magnetic field strength dependence on the distance from the central black hole. Our results indicate a deviation from the standard BK model, particularly in the decrease of the brightness temperature with the observing frequency. Either bulk acceleration of the jet material, energy transfer from the magnetic field to the particles, or both are required to explain the observations.

References in corpus (83)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Planck 2015 results. XIII. Cosmological parameters
• First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
• Theory of Star Formation
• The SIMBAD astronomical database
• First Sagittarius A* Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole in the Center of the Milky Way
• 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
• 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
• AGN Black Hole Masses and Bolometric Luminosities
• First M87 Event Horizon Telescope Results. VIII. Magnetic Field Structure near The Event Horizon
• First Sagittarius A* Event Horizon Telescope Results. VI: Testing the Black Hole Metric
• First Sagittarius A* Event Horizon Telescope Results. V. Testing Astrophysical Models of the Galactic Center Black Hole
• MOJAVE: Monitoring of Jets in Active Galactic Nuclei with VLBA Experiments. VI. Kinematics Analysis of a Complete Sample of Blazar Jets
• First M87 Event Horizon Telescope Results. VII. Polarization of the Ring
• Magnetic Fields in Spiral Galaxies
• First Sagittarius A* Event Horizon Telescope Results. III: Imaging of the Galactic Center Supermassive Black Hole
• Doppler factors, Lorentz factors and viewing angles for quasars, BL Lacertae objects and radio galaxies
• Sub-milliarcsecond Imaging of Quasars and Active Galactic Nuclei III. Kinematics of Parsec-Scale Radio Jets
• Sub-milliarcsecond Imaging of Quasars and Active Galactic Nuclei. IV. Fine Scale Structure
• First Sagittarius A* Event Horizon Telescope Results. II. EHT and Multi-wavelength Observations, Data Processing, and Calibration
• First Sagittarius A* Event Horizon Telescope Results. IV. Variability, Morphology, and Black Hole Mass
• Kinematics of Parsec-Scale Jets of Gamma-Ray Blazars at 43~GHz within the VLBA-BU-BLAZAR Program
• 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
• MOJAVE: XV. VLBA 15 GHz Total Intensity and Polarization Maps of 437 Parsec-Scale AGN Jets From 1996-2017
• RadioAstron -- a Telescope with a Size of 300 000 km: Main Parameters and First Observational Results
• High Resolution Linear Polarimetric Imaging for the Event Horizon Telescope
• Magnetic Driving of Relativistic Outflows in Active Galactic Nuclei. I. Interpretation of Parsec-Scale Accelerations
• The VLBA Imaging and Polarimetry Survey at 5 GHz
• Relativistic Beaming and the Intrinsic Properties of Extragalactic Radio Jets
• MOJAVE - XIV. Shapes and opening angles of AGN jets
• 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
• Event Horizon Telescope observations of the jet launching and collimation in Centaurus A
• Single-epoch VLBI imaging study of bright active galactic nuclei at 2 and 8 GHz
• Kinematics of Parsec-Scale Jets of Gamma-Ray Bright Blazars at 43 GHz during Ten Years of the VLBA-BU-BLAZAR Program
• Intrinsic Brightness Temperatures of AGN Jets
• MOJAVE: XVIII. Kinematics and Inner Jet Evolution of Bright Radio-Loud Active Galaxies
• Polarimetric properties of Event Horizon Telescope targets from ALMA
• MOJAVE XIX: Brightness Temperatures and Intrinsic Properties of Blazar Jets
• RadioAstron Observations of the Quasar 3C273: a Challenge to the Brightness Temperature Limit
• First M87 Event Horizon Telescope Results. IX. Detection of Near-horizon Circular Polarization
• State-of-the-art energetic and morphological modelling of the launching site of the M87 jet
• Theory and Simulations of Refractive Substructure in Resolved Scatter-Broadened Images
• Radio observations of active galactic nuclei with mm-VLBI
• F-GAMMA: Variability Doppler factors of blazars from multiwavelength monitoring
• Collimation, Acceleration and Recollimation Shock in the Jet of Gamma-Ray-emitting Radio-Loud Narrow-Line Seyfert 1 Galaxy 1H 0323+342
• Monitoring the Morphology of M87* in 2009-2017 with the Event Horizon Telescope
• The First Simultaneous 3.5 and 1.3mm Polarimetric Survey of Active Galactic Nuclei in the Northern Sky
• The ALMA Phasing System: A Beamforming Capability for Ultra-High-Resolution Science at (Sub)Millimeter Wavelengths
• The Supermassive Black Hole at the Heart of Centaurus A: Revealed by Gas- and Stellar Kinematics
• Calibration of ALMA as a phased array: ALMA observations during the 2017 VLBI campaign
• Jet Acceleration by Tangled Magnetic Fields
• The VSOP 5 GHz Active Galactic Nucleus Survey: V. Imaging Results for the Remaining 140 sources
• EHT-HOPS pipeline for millimeter VLBI data reduction
• Resolving the inner parsec of the blazar J1924-2914 with the Event Horizon Telescope
• Dual-frequency VLBI study of Centaurus A on sub-parsec scales
• Extreme Brightness Temperatures and Refractive Substructure in 3C273 with RadioAstron
• Acceleration of Compact Radio Jets on Sub-parsec Scales
• Brightness temperature constraints from interferometric visibilities
• Detection statistics of the RadioAstron AGN survey
• Collimation of the relativistic jet in the quasar 3C 273
• Absence of the predicted 2022 October outburst of OJ 287 and implications for binary SMBH scenarios
• Parsec Scale Faraday-Rotation Structure Across the Jets of 9 Active Galactic Nuclei
• Exploring the disk-jet connection in NGC 315
• Interferometric Monitoring of Gamma-ray Bright AGNs I: Results of Single-epoch Multifrequency Observations
• Compact Bright Radio-loud AGNs -- III. A Large VLBA Survey at 43 GHz
• Global millimeter VLBI array survey of ultracompact extragalactic radio sources at 86 GHz
• The Event Horizon Telescope Image of the Quasar NRAO 530
• The Jets of AGN as giant co-axial cables
• Probing spacetime and accretion model for the Galactic Center: Comparison of Kerr and dilaton black hole shadows
• Ordered magnetic fields around the 3C 84 central black hole
• The jet collimation profile at high resolution in BL Lacertae
• Faraday Conversion in Turbulent Blazar Jets
• Maximum Brightness Temperature of an Incoherent Synchrotron Source : Inverse Compton Limit - a Misnomer
• Polarimetric Geometric Modeling for mm-VLBI Observations of Black Holes
• Intrinsic Brightness Temperatures of Compact Radio Jets as a Function of Frequency
• The putative center in NGC 1052
• A Statistical Description of AGN Jet Evolution from the VLBA Imaging and Polarimetry Survey (VIPS)

Cited by in corpus (5)

• Revealing a ribbon-like jet in OJ 287 with RadioAstron
• Revisiting 3C 279 jet morphology with space VLBI at 26 microarcsecond resolution
• Dim cores of radio-bright AGN jets: VLBI and Gaia astrometry pinpoint different parsec-scale features
• Magnetic field and plasma number density from radio and millimeter core measurements in AGN jets
• Unveiling the Complex Jet Dynamics in the Blazar 2021+317 through Multi-Epoch VLBI Observations