First Sagittarius A* Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole in the Center of the Milky Way

Abstract

We present the first Event Horizon Telescope (EHT) observations of Sagittarius A* (Sgr A${}^{\ast }$), the Galactic center source associated with a supermassive black hole. These observations were conducted in 2017 using a global interferometric array of eight telescopes operating at a wavelength of $\lambda =1.3\mathrm{mm}$. The EHT data resolve a compact emission region with intrahour variability. A variety of imaging and modeling analyses all support an image that is dominated by a bright, thick ring with a diameter of $51.8\pm 2.3$\,\uas (68\% credible interval). The ring has modest azimuthal brightness asymmetry and a comparatively dim interior. Using a large suite of numerical simulations, we demonstrate that the EHT images of Sgr A${}^{\ast }$ are consistent with the expected appearance of a Kerr black hole with mass $\sim 4\times 10^6{\mathrm{M}}_{\odot }$, which is inferred to exist at this location based on previous infrared observations of individual stellar orbits as well as maser proper motion studies. Our model comparisons disfavor scenarios where the black hole is viewed at high inclination ($i>50^{\circ }$), as well as non-spinning black holes and those with retrograde accretion disks. Our results provide direct evidence for the presence of a supermassive black hole at the center of the Milky Way galaxy, and for the first time we connect the predictions from dynamical measurements of stellar orbits on scales of $10^3-10^5$ gravitational radii to event horizon-scale images and variability. Furthermore, a comparison with the EHT results for the supermassive black hole M87${}^{\ast }$ shows consistency with the predictions of general relativity spanning over three orders of magnitude in central mass.

24 pages, 6 figures, published in The Astrophysical Journal Letters on May 12, 2022. See the published paper for the full authors list

References in corpus (23)

• First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
• 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
• Trigonometric Parallaxes Of High-Mass Star Forming Regions: Our View Of The Milky Way
• 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
• Advection-Dominated Accretion and the Black Hole Event Horizon
• First Sagittarius A* Event Horizon Telescope Results. III: Imaging of the Galactic Center Supermassive Black Hole
• A Metric for Rapidly Spinning Black Holes Suitable for Strong-Field Tests of the No-Hair Theorem
• 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
• Gravitational Test Beyond the First Post-Newtonian Order with the Shadow of the M87 Black Hole
• An Unambiguous Detection of Faraday Rotation in Sagittarius A*
• The mass distribution in the Galactic Centre from interferometric astrometry of multiple stellar orbits
• The Power of Imaging: Constraining the Plasma Properties of GRMHD Simulations using EHT Observations of Sgr A*
• Plasma diagnostic potential of 2p4f in N${}^{+}$ -- accurate wavelengths and oscillator strengths
• Ab Initio Horizon-Scale Simulations of Magnetically Arrested Accretion in Sagittarius A* Fed by Stellar Winds
• Millimeter light curves of Sagittarius A* observed during the 2017 Event Horizon Telescope campaign
• Disks as Inhomogeneous, Anisotropic Gaussian Random Fields

Cited by in corpus (98)

• First Sagittarius A* Event Horizon Telescope Results. III: Imaging of the Galactic Center Supermassive Black Hole
• The NANOGrav 15-year Data Set: Constraints on Supermassive Black Hole Binaries from the Gravitational Wave Background
• 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
• Shadows and gravitational weak lensing by the Schwarzschild black hole in the string cloud background with quintessential field
• Observational evidence for cosmological coupling of black holes and its implications for an astrophysical source of dark energy
• Millimeter light curves of Sagittarius A* observed during the 2017 Event Horizon Telescope campaign
• Testing Rotating Regular Metrics with EHT Results of Sgr A*
• Orbital motion near Sagittarius A* -- Constraints from polarimetric ALMA observations
• Polarimetry and Astrometry of NIR Flares as Event Horizon Scale, Dynamical Probes for the Mass of Sgr A*
• First M87 Event Horizon Telescope Results. IX. Detection of Near-horizon Circular Polarization
• Shadow and quasinormal modes of the Kerr-Newman-Kiselev-Letelier black hole
• Shadows of black holes with dark matter halo
• Observational properties of relativistic fluid spheres with thin accretion disks
• Testing strong gravitational lensing effects by supermassive compact objects with regular spacetimes
• The Image of the M87 Black Hole Reconstructed with PRIMO
• 4D scale-dependent Schwarzschild-AdS/dS black holes: study of shadow and weak deflection angle and greybody bounding
• Shape of higher-order images of equatorial emission rings around a Schwarzschild black hole: Analytical description with polar curves
• A review on analytical studies in Gravitational Lensing
• Bumblebee black holes in light of Event Horizon Telescope observations
• Constraints on charged Symmergent black hole from shadow and lensing
• Deflection angle and shadow of the Reissner-Nordström black hole with higher-order magnetic correction in Einstein-nonlinear-Maxwell fields
• Investigating effects of dark matter on photon orbits and black hole shadows
• Quasinormal modes of a holonomy corrected Schwarzschild black hole
• Resolving the inner parsec of the blazar J1924-2914 with the Event Horizon Telescope
• Hunting extra dimensions in the shadow of Sgr A*
• Light Ring behind Wormhole Throat: Geodesics, Images and Shadows
• Polarized image of a rotating black hole in Scalar-Tensor-Vector-Gravity theory
• Observation of S4716 -- a Star with a 4 yr Orbit around Sgr A*
• Shadow revisiting and weak gravitational lensing with Chern-Simons modification
• Magnetic reconnection plasmoid model for Sagittarius A* flares
• Towards VLBI Observations of Black Hole Structure
• Curvatures, Photon Spheres and Black Hole Shadows
• Dissimilar Donuts in the Sky? Effects of a Pressure Singularity on the Circular Photon Orbits and Shadow of a Cosmological Black Hole
• 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
• Null and time-like geodesics in Kerr-Newman black hole exterior
• The Event Horizon Telescope Image of the Quasar NRAO 530
• EHT observables as a tool to estimate parameters of supermassive black holes
• The Transformational Power of Frequency Phase Transfer Methods for ngEHT
• Probing spacetime and accretion model for the Galactic Center: Comparison of Kerr and dilaton black hole shadows
• Two-Temperature GRMHD Simulations of Black Hole Accretion Flows with Multiple Magnetic Loops
• Accretion of the relativistic Vlasov gas in the equatorial plane of the Kerr black hole
• Bayesian Accretion Modeling: Axisymmetric Equatorial Emission in the Kerr Spacetime
• Photonsphere, shadow, quasinormal modes, and greybody bounds of non-rotating Simpson-Visser black hole
• Lifetime of scalar cloud formation around a rotating regular black hole
• Enabling Transformational ngEHT Science via the Inclusion of 86 GHz Capabilities
• Magnetic Reconnection in Black-Hole Magnetospheres: Lepton Loading into Jets, Superluminal Radio Blobs, and Multi-wavelength Flares
• Prospects for Constraining the Yukawa Gravity with Pulsars around Sagittarius A*
• Note on fundamental physics tests from black hole imaging: Comment on "Hunting for extra dimensions in the shadow of Sagittarius A${}^{\ast }$"
• Black Holes Up Close
• Rotating Black Hole in Kalb-Ramond Gravity: Constraining Parameters by Comparison with EHT Observations of Sgr A* and M87*
• Is a black hole shadow a reliable test of the no-hair theorem?
• Loop Quantum Gravity motivated multihorizon rotating black holes
• A Characterization of the ALMA Phasing System at 345 GHz
• Shadow thermodynamics of non-linear charged Anti-de Sitter black holes
• Equivalence between two charged black holes in dynamics of orbits outside the event horizons
• Equilibrium non-selfgravitating tori around black holes in parameterised spherically symmetric spacetimes
• Dynamic and polarimetric VLBI imaging with a multiscalar approach
• A general relativistic mass-to-distance ratio for a set of megamaser AGN black holes
• Shadow thermodynamics of the Hayward-AdS black hole
• Orbital configurations of spaceborne interferometers for studying photon rings of supermassive black holes
• Shadows and quasinormal modes of a charged non-commutative black hole by different methods
• The Next Generation Event Horizon Telescope Collaboration: History, Philosophy, and Culture
• Thin accretion disk images of the black hole in symmergent gravity
• Affine perturbation series of the deflection angle of a ray near the photon sphere of a Reissner-Nordström black hole
• Shadow of Kottler black hole in the presence of plasma for a co-moving observer
• Spins of supermassive black holes M87* and SgrA* revealed from the size of dark spots in Event Horizon Telescope Images
• A first search of transients in the Galactic Center from 230 GHz ALMA observations
• Polarimetric Geometric Modeling for mm-VLBI Observations of Black Holes
• Exploring the shear viscosity in four-dimensional planar black holes beyond General Relativity
• Discovery of a Planar Black Hole Mass Scaling Relation for Spiral Galaxies
• Milky Way globular clusters on cosmological timescales. II. Interaction with the Galactic centre
• X3: a high-mass Young Stellar Object close to the supermassive black hole Sgr~A*
• Premerger localization of intermediate mass binary black holes with LISA and prospects of joint observations with Athena and LSST
• Gödel-type solutions within the $f(R,Q,P)$ gravity
• Neutrino spin and flavor oscillations in gravitational fields
• The $\text{q}$-metric naked singularity: A viable explanation for the nature of the central object in the Milky Way
• Accretion from Winds of Red Giant Branch Stars May Reveal the Supermassive Black Hole in Leo I
• Extreme Tidal Stripping May Explain the Overmassive Black Hole in Leo I: a Proof of Concept
• A Milliarcsecond-accurate Position for Sagittarius A*
• The DIVING${}^{3D}$ Survey - Deep IFS View of Nuclei of Galaxies - III. Analysis of the nuclear region of the early-type galaxies of the sample
• Optical appearance of the Schwarzschild black hole in the string cloud context
• Expanding Sgr A* dynamical imaging capabilities with an African extension to the Event Horizon Telescope
• Black Holes with Abelian and Non-Abelian Charges and Their Impact on Matter Accretion Flows
• Probing Accretion Turbulence in the Galactic Center with EHT Polarimetry
• Prospects for ray-tracing light intensity and polarization in models of accreting compact objects using a GPU
• Accretion Properties and Estimation of Spin of Galactic Black Hole Candidate Swift J1728.9-3613 with NuSTAR during its 2019 outburst
• Synchrotron emitting Komissarov torus around naked singularities
• Synchrotron emitting Komissarov torus with magnetic polarization around Kerr black holes
• Impact of the nonthermal electron radiation effects on the horizon scale image structure of Sagittarius A*
• Not all spacetime coordinates for general-relativistic ray tracing are created equal
• Accretion of supersonic magnetized winds onto black holes
• Deblurring galaxy images with Tikhonov regularization on magnitude domain
• Spherical particle orbits around a rotating black hole in massive gravity
• Effects of a modified Reissner-Nordström spacetime
• First Light: Switching on Stars at the Dawn of Time
• Gravitational wave memory in wormhole spacetimes