First Sagittarius A* Event Horizon Telescope Results. III: Imaging of the Galactic Center Supermassive Black Hole

Abstract

We present the first event-horizon-scale images and spatiotemporal analysis of Sgr A* taken with the Event Horizon Telescope in 2017 April at a wavelength of 1.3 mm. Imaging of Sgr A* has been conducted through surveys over a wide range of imaging assumptions using the classical CLEAN algorithm, regularized maximum likelihood methods, and a Bayesian posterior sampling method. Different prescriptions have been used to account for scattering effects by the interstellar medium towards the Galactic Center. Mitigation of the rapid intra-day variability that characterizes Sgr A* has been carried out through the addition of a "variability noise budget" in the observed visibilities, facilitating the reconstruction of static full-track images. Our static reconstructions of Sgr A* can be clustered into four representative morphologies that correspond to ring images with three different azimuthal brightness distributions, and a small cluster that contains diverse non-ring morphologies. Based on our extensive analysis of the effects of sparse $(u,v)$-coverage, source variability and interstellar scattering, as well as studies of simulated visibility data, we conclude that the Event Horizon Telescope Sgr A* data show compelling evidence for an image that is dominated by a bright ring of emission with a ring diameter of $\sim$ 50 $\mu$as, consistent with the expected "shadow" of a $4\times 10^6{M}_{\odot }$ black hole in the Galactic Center located at a distance of 8 kpc.

81 pages, 45 figures, published in The Astrophysical Journal Letters on May 12, 2022. See the published paper for the full authors list

References in corpus (48)

• Array Programming with NumPy
• First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
• 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
• Event-horizon-scale structure in the supermassive black hole candidate at the Galactic Centre
• 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
• Multi-Scale CLEAN deconvolution of radio synthesis images
• An Update on Monitoring Stellar Orbits in the Galactic Center
• First M87 Event Horizon Telescope Results. VII. Polarization of the Ring
• 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
• Compressed sensing imaging techniques for radio interferometry
• Imaging the Schwarzschild-radius-scale Structure of M87 with the Event Horizon Telescope using Sparse Modeling
• Radio and Millimeter Monitoring of Sgr A*: Spectrum, Variability, and Constraints on the G2 Encounter
• The Size, Shape, and Scattering of Sagittarius A* at 86 GHz: First VLBI with ALMA
• Modeling the orbital motion of Sgr A*'s near-infrared flares
• A rapidly-changing jet orientation in the stellar-mass black hole V404 Cygni
• Millimeter light curves of Sagittarius A* observed during the 2017 Event Horizon Telescope campaign
• Polarimetric properties of Event Horizon Telescope targets from ALMA
• Super-resolution Full Polarimetric Imaging for Radio Interferometry with Sparse Modeling
• Imaging an Event Horizon: Mitigation of Scattering Toward Sagittarius A*
• Jet-lag in Sgr A*: What size and timing measurements tell us about the central black hole in the Milky Way
• Dynamical Imaging with Interferometry
• Is there a Supermassive Black Hole at the Center of the Milky Way?
• The ALMA Phasing System: A Beamforming Capability for Ultra-High-Resolution Science at (Sub)Millimeter Wavelengths
• A 600 minute near-infrared lightcurve of Sagittarius A*
• The X-ray Flux Distribution of Sagittarius A* as Seen by Chandra
• Calibration of ALMA as a phased array: ALMA observations during the 2017 VLBI campaign
• Hybrid Very Long Baseline Interferometry Imaging and Modeling with Themis
• The Intrinsic Two-Dimensional Size of Sagittarius A*
• Discovery of Substructure in the Scatter-Broadened Image of Sgr A*
• Stochastic Optics: A Scattering Mitigation Framework for Radio Interferometric Imaging
• Unified Radio Interferometric Calibration and Imaging with Joint Uncertainty Quantification
• Spitzer/IRAC Observations of the Variability of Sgr A* and the Object G2 at 4.5 microns
• Selective Dynamical Imaging of Interferometric Data
• Quantifying Intrinsic Variability of Sagittarius A* using Closure Phase Measurements of the Event Horizon Telescope
• Asymmetric structure in Sgr A* at 3mm from closure phase measurements with VLBA, GBT and LMT
• Variational Image Feature Extraction for the Event Horizon Telescope
• A D-term Modeling Code (DMC) for simultaneous calibration and full-Stokes imaging of very long baseline interferometric data
• The intrinsic structure of Sagittarius A* at 1.3 cm and 7 mm
• Persistent Non-Gaussian Structure in the Image of Sagittarius A* at 86 GHz
• Disks as Inhomogeneous, Anisotropic Gaussian Random Fields

Cited by in corpus (221)

• First Sagittarius A* Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole in the Center of the Milky Way
• Horizon-scale tests of gravity theories and fundamental physics from the Event Horizon Telescope image of Sagittarius A${}^{\ast }$
• 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
• 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
• Comparing Equivalent Gravities: common features and differences
• Tests of Loop Quantum Gravity from the Event Horizon Telescope Results of Sgr A${}^{\ast }$
• Millimeter light curves of Sagittarius A* observed during the 2017 Event Horizon Telescope campaign
• Testing Rotating Regular Metrics with EHT Results of Sgr A*
• Light rings and shadows of static black holes in effective quantum gravity
• Orbital motion near Sagittarius A* -- Constraints from polarimetric ALMA observations
• First M87 Event Horizon Telescope Results. IX. Detection of Near-horizon Circular Polarization
• Superradiant evolution of the shadow and photon ring of Sgr A${}^{\star }$
• The Black Hole Explorer: Motivation and Vision
• Analytical study of gravitational lensing in Kerr-Newman black-bounce spacetime
• An Upper Limit on the Charge of the Black Hole Sgr A* from EHT Observations
• Probing the Lorentz Symmetry Violation Using the First Image of Sagittarius A*: Constraints on Standard-Model Extension Coefficients
• Shadows of black holes with dark matter halo
• Rings and images of Horndeski hairy black hole illuminated by various thin accretions
• Towards a Non-singular Paradigm of Black Hole Physics
• Kerr black holes with synchronised Proca hair: lensing, shadows and EHT constraints
• The Image of the M87 Black Hole Reconstructed with PRIMO
• Shape of higher-order images of equatorial emission rings around a Schwarzschild black hole: Analytical description with polar curves
• Investigating Loop Quantum Gravity with EHT Observational Effects of Rotating Black holes
• A review on analytical studies in Gravitational Lensing
• Filamentary structures as the origin of blazar jet radio variability
• Image reconstruction algorithms in radio interferometry: from handcrafted to learned regularization denoisers
• Resolving the inner parsec of the blazar J1924-2914 with the Event Horizon Telescope
• Images from disk and spherical accretions of hairy Schwarzschild black holes
• Observational predictions of LQG motivated polymerized black holes and constraints from Sgr A* and M87*
• Hunting extra dimensions in the shadow of Sgr A*
• Light Ring behind Wormhole Throat: Geodesics, Images and Shadows
• Black Holes with Multiple Photon Spheres
• Gravitational lensing of a Schwarzschild-like black hole in Kalb-Ramond gravity
• Asymptotically locally flat and AdS higher-dimensional black holes of Einstein-Horndeski-Maxwell gravity in the light of EHT observations: shadow behavior and deflection angle
• Polarimetric signatures of hot spots in black hole accretion flows
• Photon Ring Astrometry for Superradiant Clouds
• Multi-frequency Black Hole Imaging for the Next-Generation Event Horizon Telescope
• Images of hairy Reissner-Nordström black hole illuminated by static accretions
• Observational Signatures of Frame Dragging in Strong Gravity
• Shadow of slowly rotating Kalb-Ramond black holes
• Observational constraints on Yukawa cosmology and connection with black hole shadows
• Broadband Multi-wavelength Properties of M87 during the 2018 EHT Campaign including a Very High Energy Flaring Episode
• Selective Dynamical Imaging of Interferometric Data
• Shadow and quasinormal modes of the rotating Einstein-Euler-Heisenberg black holes
• The Galactic Center as a laboratory for theories of gravity and dark matter
• The shadow of regular black holes with asymptotically Minkowski core
• Shadow of black hole surrounded by magnetized plasma: Axion-plasmon cloud
• Influence of accretion disk on the optical appearance of the Kazakov-Solodukhin black hole
• Using Machine Learning to Link Black Hole Accretion Flows with Spatially Resolved Polarimetric Observables
• Strong deflection limit analysis of black hole lensing in inhomogeneous plasma
• Global instability by runaway collisions in nuclear stellar clusters: Numerical tests of a route for massive black hole formation
• Testing Born-Infeld $f(T)$ teleparallel gravity through Sgr A${}^{\star }$ observations
• Shadows of rotating Einstein-Maxwell-dilaton black holes surrounded by a plasma
• The Event Horizon Telescope Image of the Quasar NRAO 530
• A non-Perturbative and Background-Independent Formulation of Quadratic Gravity
• Probing spacetime and accretion model for the Galactic Center: Comparison of Kerr and dilaton black hole shadows
• Shadow of regular black hole in scalar-tensor-vector gravity theory
• Constraining spherically symmetric metrics by the gap between photon rings
• The internal Faraday screen of Sagittarius A*
• Circular orbits and thin accretion disk around a quantum corrected black hole
• Comparison of Polarized Radiative Transfer Codes used by the EHT Collaboration
• Apparent and emergent dark matter around a Schwarzschild black hole
• Bayesian Accretion Modeling: Axisymmetric Equatorial Emission in the Kerr Spacetime
• Fitting the light curves of Sagittarius A* with a hot-spot model
• The effect of scalar hair on the charged black hole with the images from accretions disk
• Signatures of regular black holes from the shadow of Sgr A* and M87*
• Light rings and shadows of static black holes in effective quantum gravity II: A new solution without Cauchy horizons
• A "coronal-mass-ejection'' model for flares in Sagittarius A*
• Schrödinger and Klein-Gordon theories of black holes from the quantization of the Oppenheimer and Snyder gravitational collapse
• Using multiobjective optimization to reconstruct interferometric data (I)
• M87: a cosmic laboratory for deciphering black hole accretion and jet formation
• Enabling Transformational ngEHT Science via the Inclusion of 86 GHz Capabilities
• Light trajectory and shadow shape in the rotating naked singularity
• Axial gravitational quasinormal modes of a self-dual black hole in loop quantum gravity
• Quantum gravity lights up spinning black holes
• Ultracompact horizonless objects in order-reduced semiclassical gravity
• Universal thermodynamic topological classes of static black holes in Conformal Killing Gravity
• General relativistic effects and the near-infrared and X-ray variability of Sgr A* I
• Mass and spin of Kerr black holes in terms of observational quantities: The dragging effect on the redshift
• Black Holes Up Close
• Testing black hole equatorial reflection symmetry using Sgr A* shadow images
• 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
• A Characterization of the ALMA Phasing System at 345 GHz
• Survey of Radiative, Two-Temperature Magnetically Arrested Simulations of the Black Hole M87* I: Turbulent Electron Heating
• AGN STORM 2: II. Ultraviolet Observations of Mrk817 with the Cosmic Origins Spectrograph on the Hubble Space Telescope
• Strong deflection of massive particles in spherically symmetric spacetimes
• Shadow Geometry of Kerr Naked Singularities
• Gravitational atoms in the braneworld scenario
• Evidence for a toroidal magnetic field in the core of 3C 84
• Gravitoelectromagnetic coupled perturbations and quasinormal modes of a charged black hole with scalar hair
• How Spatially Resolved Polarimetry Informs Black Hole Accretion Flow Models
• The Relationship Between Simulated Sub-Millimeter and Near-Infrared Images of Sagittarius A* from a Magnetically Arrested Black Hole Accretion Flow
• Dynamic and polarimetric VLBI imaging with a multiscalar approach
• Observational Appearance of a Freely-falling Star in an Asymmetric Thin-shell Wormhole
• Probing Plasma Physics with Spectral Index Maps of Accreting Black Holes on Event Horizon Scales
• A general relativistic mass-to-distance ratio for a set of megamaser AGN black holes
• Shadow thermodynamics of the Hayward-AdS black hole
• Shadow behavior of an EMSG charged black hole
• The future ability to test theories of gravity with black-hole shadows
• Spacetime-curvature induced uncertainty principle: linking the large-structure global effects to the local black hole physics
• Traces of quantum gravitational correction at third-order curvature through the black hole shadow and particle deflection at the weak field limit
• Shadows and quasinormal modes of a charged non-commutative black hole by different methods
• Hybrid GRMHD and Force-Free Simulations of Black Hole Accretion
• Bayesian Black Hole Photogrammetry
• Exploring departures from Schwarzschild black hole in $f(R)$ gravity
• The Next Generation Event Horizon Telescope Collaboration: History, Philosophy, and Culture
• Optical appearance of numerical black hole solutions in higher derivative gravity
• A multi-frequency study of sub-parsec jets with the Event Horizon Telescope
• Distinguishing black holes with and without spontaneous scalarization in Einstein-scalar-Gauss-Bonnet theories via optical features
• Novel regular black holes: geometry, source and shadow
• Constraining modified gravity theories with scalar fields using black-hole images
• Determination of the spin parameter and the inclination angle by the relativistic images in black hole image
• A general relativistic estimation of the black hole mass-to-distance ratio at the core of TXS 2226-184
• Spins of supermassive black holes M87* and SgrA* revealed from the size of dark spots in Event Horizon Telescope Images
• Dynamics and Emission Properties of Flux Ropes from Two-Temperature GRMHD Simulations with Multiple Magnetic Loops
• Propagation of light in the presence of gravity generated by static and spherically symmetric curved space-times using Maxwell equations
• A first search of transients in the Galactic Center from 230 GHz ALMA observations
• Polarimetric Geometric Modeling for mm-VLBI Observations of Black Holes
• Shadows and parameter estimation of rotating quantum corrected black holes and constraints from EHT observation of M87* and Sgr A*
• Shadows aspect of rotating black holes in the Einstein-AdS SU(N)-nonlinear sigma model
• Analyzing Deflection Angles and Photon Sphere Dynamics of Magnetically Charged Black Holes in Nonlinear Electrodynamic
• Resonant Dynamical Friction Around a Super-Massive Black Hole: Analytical Description
• Exploring the shear viscosity in four-dimensional planar black holes beyond General Relativity
• Orbital and Radiative Properties of Wandering Intermediate-Mass Black Holes in the ASTRID Simulation
• The ring-shaped shadow of rotating naked singularity with a complete photon sphere
• Energy extraction through magnetic reconnection from a Kerr-Newman black hole in perfect fluid dark matter
• Extreme lensing induces spectro-temporal correlations in black-hole signals
• Black hole photon ring beyond General Relativity: an integrable parametrization
• Free-falling test particles in a charged Kalb-Ramond black hole: gravitational Doppler effect and tidal forces
• Swarm intelligence for full Stokes dynamic imaging reconstruction of interferometric data
• Interferometric signature of higher-order images in a parametrized framework
• Event-horizon-scale Imaging of M87* under Different Assumptions via Deep Generative Image Priors
• Gravitational Lensing and Image Distortion by Buchdahl Inspired Metric in ${\mathcal{R}}^2$ Gravity
• Polarized signatures of adiabatically expanding hotspots in Sgr A*'s accretion flow
• Effects of a global monopole on thermodynamic phase transition of the charged AdS black hole
• SgrA${}^{\ast }$ spin and mass estimates through the detection of an extremely large mass-ratio inspiral
• On the analytic generalization of particle deflection in the weak field regime and shadow size in light of EHT constraints for Schwarzschild-like black hole solutions
• Gravitational lens on a static optical constant-curvature background: Its application to Weyl gravity model
• Multimodal signatures of asymptotic (A)dS Kalb-Ramond black holes: Constraints through the shadow, weak deflection angle, and topological photon spheres
• First polarization study of the M87 jet and active galactic nuclei at submillimeter wavelengths with ALMA
• Physical origin of the dark spot at the image of supermassive black hole SgrA* revealed by the EHT collaboration
• Graviton mass due to dark energy as a superconducting medium: theoretical and phenomenological aspects
• An independent hybrid imaging of Sgr A* from the data in EHT 2017 observations
• Particle dynamics and optical appearance of charged spherically symmetric black holes in bumblebee gravity
• Expanding Sgr A* dynamical imaging capabilities with an African extension to the Event Horizon Telescope
• Superradiance of rotating black holes surrounded by dark matter
• Modified Kerr black holes surrounded by dark matter spike
• Analyzing the effect of higher dimensions on the black hole silhouette, deflection angles, and PINN approximated quasinormal modes
• Remarks on the light ring images and the optical appearance of hairy black holes in Einstein-Maxwell-dilaton gravity
• Optical appearance of the Schwarzschild black hole in the string cloud context
• Imaging fermionic dark matter cores at the center of galaxies
• General Relativistic effects and the NIR variability of Sgr A* II: A systematic approach to temporal asymmetry
• Revealing a ribbon-like jet in OJ 287 with RadioAstron
• Deep learning inference with the Event Horizon Telescope III. Zingularity results from the 2017 observations and predictions for future array expansions
• Imaging the event horizon of M87* from space on different timescales
• Image of Quantum Improved Regular Kerr Black Hole and Parameter Constraints from EHT Observations
• Estimating the mass-to-distance ratio for a set of megamaser AGN black holes by employing a general relativistic method
• Semi-analytic studies of accretion disk and magnetic field geometry in M87*
• Fate of initially bound timelike geodesics in spherical boson stars
• Deep learning inference with the Event Horizon Telescope I. Calibration improvements and a comprehensive synthetic data library
• Correspondence between two gravitational lens equations in a static and spherically symmetric spacetime
• Deep learning inference with the Event Horizon Telescope II. The Zingularity framework for Bayesian artificial neural networks
• Probing Accretion Turbulence in the Galactic Center with EHT Polarimetry
• Observational signatures from higher-order images of moving hotspots in accretion disks
• Determining parameters of a spherical black hole with a thin accretion disk by observing its shadow
• Prospects of using closure traces directly for imaging in Very Long Baseline Interferometry
• The Japanese Vision for the Black Hole Explorer Mission
• Traces of quantum fuzziness on the black hole shadow and particle deflection in the multi-fractional theory of gravity
• Fractal signatures of non-Kerr spacetimes in the shadow of light-ring bifurcations
• Shadow and thin accretion disk around Ayón-Beato-García black hole coupled with cloud of strings
• Relativistic Reflection Modeling in AGN and Related Variability from PCA: A Brief Review
• Quantum parameter-mass induced scalarization of qOS-black hole in the Einstein-Gauss-Bonnet-scalar theory
• Investigating non-Keplerian motion in flare events with astrometric data
• Shadows of a generic class of spherically symmetric, static spacetimes
• Synchrotron emitting Komissarov torus with magnetic polarization around Kerr black holes
• Overlapping of photon rings in black hole imaging
• Impact of the nonthermal electron radiation effects on the horizon scale image structure of Sagittarius A*
• The surface geometry and shadow of a Schwarzschild black hole with halo
• Not all spacetime coordinates for general-relativistic ray tracing are created equal
• Quantum Gravitational Hair in Gravastars and Observational Tests
• Non-thermal Synchrotron Emission and Polarization Signatures during Black Hole Flux Eruptions
• Synthetic gravitational lens image of the Sagittarius A${}^{\ast }$ black hole with a thin disk model
• A comparative analysis of GNSS-inferred precipitable water vapour at the potential sites for the Africa Millimetre Telescope
• Shadow of quadrupole-deformed compact objects in a local dark matter shell
• Determining parameters of Kerr black holes at finite distance by shadow observation
• Regular black hole solutions in $(2+1)$-dimensional $f(R,T)$ gravity coupled to nonlinear electrodynamics
• Revisiting 3C 279 jet morphology with space VLBI at 26 microarcsecond resolution
• Limiting the Yukawa Gravity through the Black Hole Shadows of Sgr A* and M87*
• Determining parameters of Kerr-Newman black holes by shadow observation from finite distance and spatial infinity
• SgrA* spin and mass estimates through the detection of multiple extremely large mass-ratio inspirals
• Shadow of topologically charged rotating braneworld black hole
• Accreting Schwarzschild-like compact object: Plasma-photon interaction and stability
• Shadow constraints of charged black hole with scalar hair and gravitational waves from extreme mass ratio inspirals
• Characterization of black hole accretion through image moment invariants
• Microlensing Black Hole Shadows
• Perturbations of Einstein--Maxwell--phantom spacetime: Instabilities of charged Ellis--Bronnikov wormholes and quasinormal modes of black holes
• Gamma-ray emission from primordial black hole-neutron star interaction
• Deciphering signatures of Kerr-Sen black holes in presence of plasma from the Event Horizon Telescope data
• Accelerating the CLEAN algorithm of radio interferometry with convex optimization
• Charge constraint on M87* with twisted light
• Exploring black holes with multiple photon spheres by interferometric signatures
• Shadows cast by a class of rotating black bounces with an anisotropic fluid
• Parameter Inference of Black Hole Images using Deep Learning in Visibility Space
• Constraints on horizonless objects after the EHT observation of Sagittarius A*
• Orbit design for mitigating interstellar scattering effects in Earth-space VLBI observations of Sgr A*
• Macroscopic backreaction of the trace anomaly on classical vacuum backgrounds
• Investigating the interplay of the braneworld gravity and the plasma environment on the black hole shadow
• Universality in quasinormal modes of a magnetized black hole
• Optical appearance of regularized compact objects without an exterior photon sphere
• Scattering of massive particles from black holes and naked singularities
• Constructing a gravitational wave analysis pipeline for extremely large mass ratio inspirals
• Testing the black hole area law with Event Horizon Telescope
• What are the parities of photon-ring images near a black hole?
• Images of the accretion disk in Hybrid metric-Palatini gravity
• Charged black holes in Eddington-inspired Born-Infeld gravity: An in-depth analysis of the structure of spacetime geometry
• Shaving off soft hairs and the black hole image memory effect
• (In)equivalence of Metric-Affine and Metric Effective Field Theories
• Multiobjective optimization for scattering mitigation and scattering screen reconstruction in VLBI observations of the Galactic Center
• Black hole shadows in nonminimally coupled Weyl connection gravity