Pith sign in

REVIEW 12 cited by

Not yet reviewed by Pith; the record is open.

This paper has not been read by Pith yet. Machine review is queued; the pith claim, tier, and objections will appear here once it completes.

SPECIMEN: schema-true, not a live event

T0 review · schema-true

One-sentence machine reading of the paper's core claim.

pith:XXXXXXXX · record.json · timestamp

arxiv 2105.01173 v2 pith:WAGPPLGO submitted 2021-05-03 astro-ph.HE astro-ph.GA

First M87 Event Horizon Telescope Results. VIII. Magnetic Field Structure near The Event Horizon

classification astro-ph.HE astro-ph.GA
keywords magneticemissionmodelspolarizationblackeventfieldshole
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved
0 comments
read the original abstract

Event Horizon Telescope (EHT) observations at 230 GHz have now imaged polarized emission around the supermassive black hole in M87 on event-horizon scales. This polarized synchrotron radiation probes the structure of magnetic fields and the plasma properties near the black hole. Here we compare the resolved polarization structure observed by the EHT, along with simultaneous unresolved observations with the Atacama Large Millimeter/submillimeter Array, to expectations from theoretical models. The low fractional linear polarization in the resolved image suggests that the polarization is scrambled on scales smaller than the EHT beam, which we attribute to Faraday rotation internal to the emission region. We estimate the average density n_e of order 10^4-7 cm-3, magnetic field strength B of order 1-30 G, and electron temperature Te of order (1-12) x 10^10 K of the radiating plasma in a simple one-zone emission model. We show that the net azimuthal linear polarization pattern may result from organized, poloidal magnetic fields in the emission region. In a quantitative comparison with a large library of simulated polarimetric images from general relativistic magnetohydrodynamic (GRMHD) simulations, we identify a subset of physical models that can explain critical features of the polarimetric EHT observations while producing a relativistic jet of sufficient power. The consistent GRMHD models are all of magnetically arrested accretion disks, where near-horizon magnetic fields are dynamically important. We use the models to infer a mass accretion rate onto the black hole in M87 of (3-20) x 10^-4 Msun yr-1.

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Forward citations

Cited by 12 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score.

  1. A Jet from a Nearly Dormant Black Hole

    astro-ph.HE 2026-06 unverdicted novelty 8.0

    Multi-frequency VLBI observations detect a two-sided jet with steep synchrotron spectrum from the nearly dormant SMBH in M60, with frequency-dependent core shift locating the engine ~10 Schwarzschild radii upstream of...

  2. GRMHD accretion beyond the black hole paradigm: Light from within the shadow

    astro-ph.HE 2026-04 accept novelty 7.0

    3D GRMHD simulations of accretion onto a JMN-1 horizonless singularity produce a magnetically arrested disk with an accretion rate of ~3e-6 Eddington matching M87* observations and EHT-consistent images, plus central ...

  3. Photon rings and shadows of black holes with non-minimal couplings between curvature and electromagnetic field

    gr-qc 2026-04 conditional novelty 6.0

    Three distinct non-minimal curvature-EM couplings produce different enlargements or reductions of black hole shadows and alter photon ring separations in characteristic ways.

  4. Relative Magnification Factor of Point Sources on Accretion Disks

    gr-qc 2026-04 unverdicted novelty 6.0

    Corotating point sources on accretion disks near black holes distort the relative magnification factor distribution, modulating caustics and encoding accretion flow kinematics via time-delayed images.

  5. Probing near-zone magnetic fields with extreme mass-ratio inspirals

    gr-qc 2026-07 conditional novelty 5.0

    A magnetized Schwarzschild background shifts EMRI orbital dynamics and GW waveforms, with B~10^9 G producing ~1.3 rad dephasing over one year for a 10^6 M_sun system.

  6. Equatorial Circular Motion of Charged Test Particles in a Weakly Magnetized Taub--NUT Background

    gr-qc 2026-05 unverdicted novelty 5.0

    Derives circularity and marginal stability conditions for charged particles in weakly magnetized Taub-NUT spacetime and finds that magnetic field strength monotonically decreases the ISCO radius with charge-dependent ...

  7. Chaotic motion of particles around a Schwarzschild black hole in a swirling electromagnetic background

    gr-qc 2026-05 unverdicted novelty 5.0

    Numerical chaos indicators applied to the Schwarzschild-Bertotti-Robinson-Bonnor-Melvin family show that chaos occurs without swirling and that electromagnetic field strengths and directions tightly restrict bound orbits.

  8. Dimming of Photon Ring due to Photon-Axion Conversion around Kerr Black Holes

    gr-qc 2026-05 unverdicted novelty 5.0

    Photon-axion conversion near Kerr black holes produces dimming of photon spectral luminosity that increases with black hole spin, magnetic field strength, and photon-axion coupling, most efficiently at high frequencies.

  9. Photon Propagation and Black Hole Imaging in Kruglov Nonlinear Electrodynamics

    gr-qc 2026-04 unverdicted novelty 5.0

    In Kruglov nonlinear electrodynamics, small positive values of the parameter q produce stable photon orbits outside the event horizon and modify black hole shadows and relativistic images even when the spacetime metri...

  10. Photon Propagation and Black Hole Imaging in Kruglov Nonlinear Electrodynamics

    gr-qc 2026-04 unverdicted novelty 5.0

    In Kruglov's Born-Infeld-type nonlinear electrodynamics, the effective photon geometry around a charged black hole produces q-dependent shifts in light deflection, shadow radius, and accretion disk images, including s...

  11. Investigating the interplay of the braneworld gravity and the plasma environment on the black hole shadow

    gr-qc 2025-12 unverdicted novelty 4.0

    Negative tidal charge enlarges the shadow of rotating braneworld black holes while inhomogeneous plasma shrinks it and homogeneous plasma enlarges it; EHT data limits q to roughly -1.15 to 0.45 for M87* in the low-den...

  12. Polarization Signatures from GRMHD Simulations of Black Hole Accretion

    astro-ph.HE 2026-05 unverdicted novelty 2.0

    Polarization signatures from GRMHD simulations of black hole accretion can help probe disk, corona, and jet properties when combined with X-ray polarimetry observations.