Spatially resolved origin of mm-wave linear polarization in the nuclear region of 3C 84

Abstract

We report results from a deep polarization imaging of the nearby radio galaxy 3C84 (NGC1275). The source was observed with the Global Millimeter VLBI Array (GMVA) at 86GHz at an ultra-high angular resolution of $50\mu$as (corresponding to 250$R_s$). We also add complementary multi-wavelength data from the Very Long Baseline Array (VLBA; 15 & 43GHz) and from the Atacama Large Millimeter/submillimeter Array (ALMA; 97.5, 233.0, and 343.5GHz). At 86GHz, we measure a fractional linear polarization of $\sim 2$% in the VLBI core region. The polarization morphology suggests that the emission is associated with an underlying limb-brightened jet. The fractional linear polarization is lower at 43 and 15GHz ($\sim 0.3-0.7$% and $<0.1$%, respectively). This suggests an increasing linear polarization degree towards shorter wavelengths on VLBI scales. We also obtain a large rotation measure (RM) of $\sim 10^{5-6}rad/{\mathrm{m}}^2$ in the core at $\gtrsim$43GHz. Moreover, the VLBA 43GHz observations show a variable RM in the VLBI core region during a small flare in 2015. Faraday depolarization and Faraday conversion in an inhomogeneous and mildly relativistic plasma could explain the observed linear polarization characteristics and the previously measured frequency dependence of the circular polarization. Our Faraday depolarization modeling suggests that the RM most likely originates from an external screen with a highly uniform RM distribution. To explain the large RM value, the uniform RM distribution, and the RM variability, we suggest that the Faraday rotation is caused by a boundary layer in a transversely stratified jet. Based on the RM and the synchrotron spectrum of the core, we provide an estimate for the magnetic field strength and the electron density of the jet plasma.

arXiv comment19 pages, 17 figures, 8 tables, accepted for publication in Astronomy & Astrophysics

References in corpus (61)

• Hot Accretion Flows Around Black Holes
• General Relativistic Magnetohydrodynamic Simulations of Magnetically Choked Accretion Flows around Black Holes
• Polarimetric Observations of 15 Active Galactic Nuclei at High Frequencies: Jet Kinematics from Bimonthly Monitoring with the Very Long Baseline Array
• Blazars in the Fermi Era: The OVRO 40-m Telescope Monitoring Program
• DiFX2: A more flexible, efficient, robust and powerful software correlator
• Turbulent, Extreme Multi-Zone Model for Simulating Flux and Polarization Variability in Blazars
• Jet Launching Structure Resolved Near the Supermassive Black Hole in M87
• MOJAVE: Monitoring of Jets in AGN with VLBA Experiments. V. Multi-epoch VLBA Images
• 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
• Polarization and structure of relativistic parsec-scale AGN jets
• MOJAVE: Monitoring of Jets in Active Galactic Nuclei with VLBA Experiments. VIII. Faraday rotation in parsec-scale AGN jets
• Resolved Magnetic-Field Structure and Variability Near the Event Horizon of Sagittarius A*
• Fermi Discovery of Gamma-Ray Emission from NGC 1275
• The limb-brightened jet of M87 down to 7 Schwarzschild radii scale
• Multiwaveband Polarimetric Observations of 15 Active Galactic Nuclei at High Frequencies: Correlated Polarization Behavior
• Optical and Radio Polarimetry of the M87 Jet at 0.2" Resolution
• VLBA Absorption Imaging of Ionized Gas Associated with the Accretion Disk in NGC 1275
• Probing the innermost regions of AGN jets and their magnetic fields with RadioAstron. I. Imaging BL Lacertae at 21 microarcsecond resolution
• 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
• Synchrotron radiation of self-collimating relativistic MHD jets
• The Spectrum and Variability of Circular Polarization in Sagittarius A* from 1.4 to 15 GHz
• Three dimensional magnetic field structure of six parsec-scale active galactic nuclei jets
• Faraday rotation in GRMHD simulations of the jet launching zone of M87
• Faraday rotation and polarization gradients in the jet of 3C~120: Interaction with the external medium and a helical magnetic field?
• Kinematics and Excitation of the Molecular Hydrogen Accretion Disc in NGC 1275
• Erratic Jet Wobbling in the BL Lacertae Object OJ287 Revealed by Sixteen Years of 7mm VLBA Observations
• Faraday Rotation Measure Gradients from a Helical Magnetic Field in 3C 273
• Detection of intrinsic source structure at ~3 Schwarzschild radii with Millimeter-VLBI observations of SAGITTARIUS A*
• Radio observations of active galactic nuclei with mm-VLBI
• Relativistic Outflow Drives Gamma-Ray Emission in 3C345
• POLAMI: Polarimetric Monitoring of Active Galactic Nuclei at Millimetre Wavelengths. III. Characterisation of total flux density and polarisation variability of relativistic jets
• POLAMI: Polarimetric Monitoring of Active Galactic Nuclei at Millimetre Wavelengths. I. The program, calibration, and calibrators data products
• Signatures of large-scale magnetic fields in AGN jets: transverse asymmetries
• A multi-wavelength polarimetric study of the blazar CTA 102 during a Gamma-ray flare in 2012
• A strong magnetic field in the jet base of a supermassive black hole
• Location of Gamma-ray emission and magnetic field strengths in OJ 287
• The First Simultaneous 3.5 and 1.3mm Polarimetric Survey of Active Galactic Nuclei in the Northern Sky
• Through The Ring Of Fire: $\gamma$-Ray Variability In Blazars By A Moving Plasmoid Passing A Local Source Of Seed Photons
• A 3.5mm Polarimetric Survey of Radio-loud Active Galactic Nuclei
• XPOL - the correlation polarimeter at the IRAM 30m telescope
• Polarization measurements analysis I. Impact of the full covariance matrix on polarization fraction and angle measurements
• 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
• On the Calibration of Full-polarization 86GHz Global VLBI Observations
• POLAMI: Polarimetric Monitoring of Active Galactic Nuclei at Millimetre Wavelengths. II. Widespread circular polarisation
• The Circular Polarization of Sagittarius A* at Submillimeter Wavelengths
• Theoretical Models for Producing Circularly Polarized Radiation in Extragalactic Radio Sources
• High Levels of Circularly Polarized Emission from the Radio Jet in NGC 1275 (3C 84)
• Probing the Parsec-scale Accretion Flow of 3C 84 with Millimeter Polarimetry
• Full-Stokes polarimetry with circularly polarized feeds - Sources with stable linear and circular polarization in the GHz regime
• Connection between inner jet kinematics and broadband flux variability in the BL Lac object S5 0716+714
• KVN observations suggest multiple $\gamma$-ray emission regions in 3C 84
• Enhanced Polarized Emission from the One-Parsec-Scale Hotspot of 3C 84 as a Result of the Interaction with Clumpy Ambient Medium
• Parsec Scale Faraday-Rotation Structure Across the Jets of 9 Active Galactic Nuclei
• High-frequency radio polarization measurements of WMAP point sources
• Faraday Conversion in Turbulent Blazar Jets
• Interpreting the time variable RM observed in the core region of the TeV blazar Mrk 421
• Discovery of off-axis jet structure of TeV blazar Mrk 501 with mm-VLBI
• A search for linear polarization in the active galactic nucleus 3C 84 at 239 and 348 GHz

Cited by in corpus (29)

• Relativistic Jets in Active Galactic Nuclei
• The Accretion flow in M87 is really MAD
• Decomposing the Internal Faraday Rotation of Black Hole Accretion Flows
• Black Hole Magnetic Fields and Their Imprint on Circular Polarization Images
• Ray-Tracing in Relativistic Jet Simulations: A Polarimetric Study of Magnetic Field Morphology and Electron Scaling Relations
• Pinpointing the jet apex of 3C 84
• The TeV-emitting radio galaxy 3C 264. VLBI kinematics and SED modeling
• 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
• RadioAstron discovery of a mini-cocoon around the restarted parsec-scale jet in 3C 84
• Enabling Transformational ngEHT Science via the Inclusion of 86 GHz Capabilities
• Jet kinematics in the transversely stratified jet of 3C 84 A two-decade overview
• 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
• A persistent double nuclear structure in 3C 84
• New jet feature in the parsec-scale jet of the blazar OJ287 connected to the 2017 teraelectronvolt flaring activity
• 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
• Possible Evidence of a Universal Radio/X-ray Correlation in a near-Complete Sample of Hard X-ray Selected Seyfert Galaxies
• Using variability and VLBI to measure cosmological distances
• Polarization Observations of AGN Jets: Past and Future
• Observing the Time Evolution of the Multi-Component Nucleus of 3C\,84
• Two-dimensional Particle-in-Cell simulations of axisymmetric black hole magnetospheres: angular dependence of the Blandford-Znajek flux
• Probing the Heart of Active Narrow-line Seyfert 1 Galaxies with VERA Wideband Polarimetry
• The dynamics of the parsec-scale jet in the neutrino blazar PKS 0735+178
• A revised view of the linear polarization in the subparsec core of M87 at 7 mm
• Detection of Compton scattering in the jet of 3C 84
• Where within the 3C 84 jet are $\gamma$-rays produced?
• From electrons to Janskys: Full stokes polarized radiative transfer in 3D relativistic particle-in-cell jet simulations