REVIEW 21 cited by
Observing the Inner Shadow of a Black Hole: A Direct View of the Event Horizon
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
Observing the Inner Shadow of a Black Hole: A Direct View of the Event Horizon
read the original abstract
Simulated images of a black hole surrounded by optically thin emission typically display two main features: a central brightness depression and a narrow, bright "photon ring" consisting of strongly lensed images superposed on top of the direct emission. The photon ring closely tracks a theoretical curve on the image plane corresponding to light rays that asymptote to unstably bound photon orbits around the black hole. This critical curve has a size and shape that are purely governed by the Kerr geometry; in contrast, the size, shape, and depth of the observed brightness depression all depend on the details of the emission region. For instance, images of spherical accretion models display a distinctive dark region -- the "black hole shadow" -- that completely fills the photon ring. By contrast, in models of equatorial disks extending to the black hole's event horizon, the darkest region in the image is restricted to a much smaller area -- an inner shadow -- whose edge lies near the direct lensed image of the equatorial horizon. Using both semi-analytic models and general relativistic magnetohydrodynamic (GRMHD) simulations, we demonstrate that the photon ring and inner shadow may be simultaneously visible in submillimeter images of M87*, where magnetically arrested disk (MAD) simulations predict that the emission arises in a thin region near the equatorial plane. We show that the relative size, shape, and centroid of the photon ring and inner shadow can be used to estimate the black hole mass and spin, breaking degeneracies in measurements of these quantities that rely on the photon ring alone. Both features may be accessible to direct observation via high-dynamic-range images with a next-generation Event Horizon Telescope.
Forward citations
Cited by 21 Pith papers
-
Light Propagation Prescriptions for Black Hole Movies
Brisk light bridges fast and slow prescriptions by using dominant temporal intervals per lensing band, with mismatches reaching tens of percent when source variability is shorter than delay spreads.
-
GRMHD accretion beyond the black hole paradigm: Light from within the shadow
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 ...
-
Novel extended inner shadow in images of Johannsen-Psaltis black holes with thin accretion disks
JP black holes with non-closed horizons produce an 'extended inner shadow' distinct from the ordinary inner shadow, and all image scales (inner shadow, photon ring, peak positions) grow monotonically with |ϵ3|.
-
Black Hole Photon Rings Saturate the Quantum Chaos Bound
Photon rings around black holes saturate the quantum chaos bound via Lyapunov exponents of null geodesics and OTOCs in the near-ring region.
-
Light Propagation Prescriptions for Black Hole Movies
When source variability is comparable to Kerr geodesic delay spreads, high-inclination fast- and slow-light curves can differ by tens of percent; brisk light retains leading lensing timing more cheaply.
-
Reshaping the inner shadow of a Kerr black hole by a torn accretion disk
Torn accretion disks around Kerr black holes erode the inner shadow and produce bifurcated, crescent, and multi-order ring morphologies hard to obtain with standard equatorial disks.
-
Reshaping the inner shadow of a Kerr black hole by a torn accretion disk
Torn accretion disks around Kerr black holes erode the inner shadow and create bifurcated, crescent, and multi-ring shadow features driven by sub-disk discontinuities and outer tilt angle.
-
Critical phenomenon inside asymptotically flat black holes with spontaneous scalarization
Scalarized black holes in EMS theory lack smooth Cauchy horizons and form Kasner singularities, with a scaling relation between Kasner parameter and charge-to-mass ratio near criticality.
-
Optical Images of the Braneworld Black Hole Surrounded by an Optically Thin Accretion Disk
A rotating braneworld black hole with tidal charge casts an asymmetric, spin- and q-dependent shadow; with the adopted disk emissivity, its 86 GHz image is brighter than its 230 GHz image.
-
Distorting Kerr Images with Parity-Odd Scalar Hair
Numerical study of thin accretion disk images shows that increasing parity-odd scalar hair on Kerr black holes shrinks and distorts the photon ring and shadow, producing multiple disconnected shadows and chaotic lensi...
-
Strong-field signatures of a regular black hole in an Einasto dark matter halo
Regular black holes in Einasto dark matter halos show the strongest deviations from Schwarzschild in photon sphere and shadow properties near a critical halo parameter, remaining consistent with Sgr A* but mildly disf...
-
Probing Lorentz-violating effects via precession and accretion disk images of a rotating bumblebee black hole
Lorentz violation in a rotating bumblebee black hole suppresses Lense-Thirring precession, increases periastron precession, shrinks the inner shadow, and enhances the lensed ring while leaving the critical curve nearl...
-
Shadow signatures and energy accumulation in Lorentzian-Euclidean black holes
Lorentzian-Euclidean black holes produce excess inner-shadow intensity and accumulate energy at the horizon with backreaction unlike stable light rings.
-
Imaging and Polarimetric Signatures of Konoplya-Zhidenko Black Holes with Various Thick Disk
Horizon-scale synchrotron images and polarization maps of Konoplya-Zhidenko black holes with thick disks show expanded photon rings, darker centers, and viewing-angle-dependent asymmetries that vary with the deformati...
-
Plasma-Induced Modifications of the Shadows of Rotating Bardeen Black Holes with Perfect Fluid Dark Matter
The shadow of a rotating Bardeen black hole in perfect-fluid dark matter shrinks and deforms with plasma density, and EHT data can constrain the plasma and dark-matter parameters.
-
Optical Appearance of the Kerr-Bertotti-Robinson Black Hole with a Magnetically Driven Synchrotron Emissivity Model
Kerr-BR black hole images with magnetically coupled synchrotron emissivity show spin- and B-dependent shifts in the inner disk edge, altered lensing rings, and Doppler asymmetries, with retrograde cases displaying wid...
-
Optical images of Kerr-Sen black hole illuminated by thick accretion disks
Increasing charge Q shrinks photon rings and central shadows in Kerr-Sen black hole images while spin creates brightness asymmetry; polarization patterns follow lensing and frame dragging.
-
Unveiling Inner Shadows and Polarization Signatures of Rotating Einstein-Gauss-Bonnet Black Holes
Numerical backward ray-tracing shows that the inner shadow size shrinks with the Gauss-Bonnet coupling while polarization direction near the shadow and photon ring shifts noticeably, and combining both observables yie...
-
Observational Signatures of Rotating Ay\'{o}n-Beato-Garc\'{i}a Black Holes: Shadows, Accretion Disks and Images
Rotating Ayón-Beato–García black holes cast smaller, spin-asymmetric shadows whose diameters, compared with EHT data, bound the nonlinear-electrodynamics charge while leaving Kerr viable.
-
Observational Signatures of Rotating Ay\'{o}n-Beato-Garc\'{i}a Black Holes: Shadows, Accretion Disks and Images
Rotating Ayón-Beato-García black holes produce smaller and sometimes D-shaped shadows whose size constrains the charge parameter ζ to the range 0.132811M–0.213607M when matched to EHT observations of M87* and Sgr A*.
-
Probing Kalb-Ramond gravity with charged rotating black holes: constraints from EHT observations
EHT shadow observations constrain the Lorentz-violating parameter ℓ in Kalb-Ramond gravity for charged rotating black holes to roughly |ℓ| ≲ 0.1-0.2, with an upper bound ℓ ≲ 0.19 from Sgr A*.
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.