DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole

Journal Article · · The Astrophysical Journal. Letters (Online)
ORCiD logo; ORCiD logo; ; ; ORCiD logo; ORCiD logo; ; ORCiD logo; ORCiD logo; ; ORCiD logo; ; ORCiD logo; ORCiD logo; ; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; more »; ; ORCiD logo; ; ORCiD logo; ORCiD logo; ORCiD logo; ; ; ; ORCiD logo; ORCiD logo; ORCiD logo; ; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ; ORCiD logo; ; ; ; ORCiD logo; ORCiD logo; ORCiD logo; ; ; ORCiD logo; ; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ; ORCiD logo; ORCiD logo; ; ORCiD logo; ORCiD logo; ; ; ORCiD logo; ; ORCiD logo; ORCiD logo; ; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ; ; ORCiD logo; ; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ; ORCiD logo; ; ORCiD logo; ORCiD logo; ; ORCiD logo; ; ; ORCiD logo; ; ORCiD logo; ORCiD logo; ; ; ; ORCiD logo; ORCiD logo; ORCiD logo; ; ORCiD logo; ORCiD logo; ORCiD logo; ; ORCiD logo; ; ORCiD logo; ORCiD logo; ; ORCiD logo; ORCiD logo; ; ; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ; ORCiD logo; ORCiD logo; ORCiD logo; ; ; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ; ORCiD logo; ; ORCiD logo; ORCiD logo; ORCiD logo; ; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ; ORCiD logo; ORCiD logo; ORCiD logo; ; ORCiD logo; ; ORCiD logo; ORCiD logo; ; ; ORCiD logo; ; ; ORCiD logo « less

We present the first Event Horizon Telescope (EHT) images of M87, using observations from April 2017 at 1.3 mm wavelength. These images show a prominent ring with a diameter of ~40 μas, consistent with the size and shape of the lensed photon orbit encircling the "shadow" of a supermassive black hole. The ring is persistent across four observing nights and shows enhanced brightness in the south. To assess the reliability of these results, we implemented a two-stage imaging procedure. In the first stage, four teams, each blind to the others' work, produced images of M87 using both an established method (CLEAN) and a newer technique (regularized maximum likelihood). This stage allowed us to avoid shared human bias and to assess common features among independent reconstructions. In the second stage, we reconstructed synthetic data from a large survey of imaging parameters and then compared the results with the corresponding ground truth images. This stage allowed us to select parameters objectively to use when reconstructing images of M87. Across all tests in both stages, the ring diameter and asymmetry remained stable, insensitive to the choice of imaging technique. We describe the EHT imaging procedures, the primary image features in M87, and the dependence of these features on imaging assumptions.

Research Organization:
Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
Sponsoring Organization:
USDOE Laboratory Directed Research and Development (LDRD) Program
Contributing Organization:
The Event Horizon Telescope Collaboration
Grant/Contract Number:
89233218CNA000001
OSTI ID:
1571628
Report Number(s):
LA-UR-19-30387; TRN: US2100335
Journal Information:
The Astrophysical Journal. Letters (Online), Vol. 875, Issue 1; ISSN 2041-8213
Publisher:
Institute of Physics (IOP)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 323 works
Citation information provided by
Web of Science

References (104)

The Innermost Collimation Structure of the m87 jet down to ∼10 Schwarzschild Radii journal September 2013
The Black hole mass in m87 from Gemini/Nifs Adaptive Optics Observations journal February 2011
The Inner Jet of the Radio Galaxy [OBJECTNAME STATUS="LINKS"]M87[/OBJECTNAME] journal September 2007
The Structure and Dynamics of the Subparsec Jet in M87 Based on 50 VLBA Observations over 17 Years at 43 GHz journal March 2018
Compressed sensing imaging techniques for radio interferometry text January 2008
Die Wahrscheinliche Schwingungsverteilung in Einer von Einer Lichtquelle Direkt Oder Mittels Einer Linse Beleuchteten Ebene journal January 1934
Pilot KaVA monitoring on the M 87 jet: Confirming the inner jet structure and superluminal motions at sub-pc scales journal July 2017
Long-term millimeter VLBI monitoring of M 87 with KVN at milliarcsecond resolution: nuclear spectrum journal February 2018
Testing the No-Hair Theorem with Observations in the Electromagnetic Spectrum. ii. Black hole Images journal June 2010
The ALMA Phasing System: A Beamforming Capability for Ultra-high-resolution Science at (Sub)Millimeter Wavelengths journal December 2017
The inner halo of M 87: a first direct view of the red-giant population journal November 2010
The Scattering and Intrinsic Structure of Sagittarius A* at Radio Wavelengths text January 2018
meqsilhouette: a mm-VLBI observation and signal corruption simulator journal September 2016
HIGH-SENSITIVITY 86 GHz (3.5 mm) VLBI OBSERVATIONS OF M87: DEEP IMAGING OF THE JET BASE AT A RESOLUTION OF 10 SCHWARZSCHILD RADII journal January 2016
Spread spectrum for imaging techniques in radio interferometry journal December 2009
Relaxing the isoplanatism assumption in self-calibration; applications to low-frequency radio interferometry journal July 1984
Kinematics of the jet in M 87 on scales of 100–1000 Schwarzschild radii journal October 2016
Viewing the Shadow of the Black Hole at the Galactic Center text January 1999
Super-resolution imaging with radio interferometry using sparse modeling journal September 2014
The Black hole Mass, Stellar Mass-To-Light Ratio, and dark halo in m87 journal July 2009
The Scattering and Intrinsic Structure of Sagittarius A* at Radio Wavelengths journal September 2018
High Resolution Linear Polarimetric Imaging for the Event Horizon Telescope text January 2016
First M87 Event Horizon Telescope Results. VI. The Shadow and Mass of the Central Black Hole journal April 2019
Image reconstruction from incomplete and noisy data journal April 1978
Imaging the Schwarzschild-radius-scale Structure of M87 with the Event Horizon Telescope Using Sparse Modeling journal March 2017
Resolved magnetic-field structure and variability near the event horizon of Sagittarius A journal December 2015
An interferometry imaging beauty contest conference October 2004
Interferometry and Synthesis in Radio Astronomy book January 2017
Jet-Launching Structure Resolved Near the Supermassive Black Hole in M87 journal September 2012
The Structure of the m87 jet: a Transition from Parabolic to Conical Streamlines journal January 2012
Capabilities and prospects of the East Asia Very Long Baseline Interferometry Network journal January 2018
First M87 Event Horizon Telescope Results. II. Array and Instrumentation text January 2019
INTERFEROMETRIC MONITORING OF GAMMA-RAY BRIGHT AGNs. I. THE RESULTS OF SINGLE-EPOCH MULTIFREQUENCY OBSERVATIONS journal November 2016
First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole text January 2019
The m87 Black hole mass from Gas-Dynamical Models of Space Telescope Imaging Spectrograph Observations journal May 2013
Testing General Relativity with the Shadow Size of Sgr A* text January 2015
Multiscale CLEAN Deconvolution of Radio Synthesis Images journal October 2008
A new view on the M 87 jet origin: Turbulent loading leading to large-scale episodic wiggling journal April 2017
The Structure and Dynamics of the Sub-parsec Scale Jet in M87 Based on 50 VLBA Observations Over 17 Years at 43 GHz text January 2018
Indication of the Black hole Powered jet in m87 by vsop Observations journal December 2016
MOJAVE. XIII. PARSEC-SCALE AGN JET KINEMATICS ANALYSIS BASED ON 19 YEARS OF VLBA OBSERVATIONS AT 15 GHz journal June 2016
Atmospheric transmission at microwaves (ATM): an improved model for millimeter/submillimeter applications journal January 2001
Linear polarization radio imaging at milliarcsecond resolution journal May 1994
Direct Maximum-Entropy Image Reconstruction from the Bispectrum journal January 1994
The acs Fornax Cluster Survey. v. Measurement and Recalibration of Surface Brightness Fluctuations and a Precise Value of the Fornax-Virgo Relative Distance journal March 2009
Optical and Radio Polarimetry of the M87 Jet at 0[farcs]2 Resolution journal May 1999
Dual differential polarimetry. A technique to recover polarimetric information from dual polarization observations text January 2016
The Jet of M87 at Tenth‐Arcsecond Resolution: Optical, Ultraviolet, and Radio Observations journal December 1996
First M87 Event Horizon Telescope Results. V. Physical Origin of the Asymmetric Ring text January 2019
Mapping radio sources with uncalibrated visibility data journal May 1980
Compressed sensing imaging techniques for radio interferometry journal May 2009
Milliarcsecond-Scale Spectral Properties and Jet Motions in M 87 journal April 2006
230 GHz VLBI OBSERVATIONS OF M87: EVENT‐HORIZON‐SCALE STRUCTURE DURING AN ENHANCED VERY‐HIGH‐ENERGY $\gamma $‐RAY STATE IN 2012 journal July 2015
The Next Generation Virgo Cluster Survey (NGVS). XVIII. Measurement and Calibration of Surface Brightness Fluctuation Distances for Bright Galaxies in Virgo (and Beyond) text January 2018
Principles of image reconstruction in optical interferometry: tutorial journal January 2017
The MeqTrees software system and its use for third-generation calibration of radio interferometers journal November 2010
Image Formation by Self-Calibration in Radio Astronomy journal September 1984
Testing General Relativity with the Shadow Size of Sgr A * journal January 2016
Mojave: Monitoring of jets in Active Galactic Nuclei with vlba Experiments. xi. Spectral Distributions journal May 2014
The limb-brightened jet of M87 down to the 7 Schwarzschild radii scale journal August 2018
PRECL: A new method for interferometry imaging from closure phase journal April 2016
Jet Launching Structure Resolved Near the Supermassive Black Hole in M87 text January 2012
First M87 Event Horizon Telescope Results. II. Array and Instrumentation journal April 2019
A novel image reconstruction software for optical/infrared interferometry conference July 2010
A new method for making maps with unstable radio interferometers journal October 1981
Reconstructing Video of Time-Varying Sources From Radio Interferometric Measurements journal December 2018
An origin of the radio jet in M87 at the location of the central black hole journal September 2011
Viewing the Shadow of the Black Hole at the Galactic Center journal January 2000
The Parabolic jet Structure in m87 as a Magnetohydrodynamic Nozzle journal September 2013
Parabolic Jets from the Spinning Black Hole in M87 journal December 2018
Principles of image reconstruction in optical interferometry: tutorial text January 2017
The Supermassive Black Hole of M87 and the Kinematics of Its Associated Gaseous Disk journal November 1997
A High‐Resolution X‐Ray Image of the Jet in M87 journal January 2002
Hubble Space Telescope Observations of Superluminal Motion in the M87 Jet journal August 1999
High-Resolution Linear Polarimetric Imaging for the Event Horizon Telescope journal September 2016
Fringe detection methods for very long baseline arrays journal March 1995
First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole journal April 2019
Parabolic Jets from the Spinning Black Hole in M87 text January 2018
Kinematics of Parsec-scale Jets of Gamma-Ray Blazars at 43 GHz within the VLBA-BU-BLAZAR Program journal September 2017
High-resolution, high dynamic range VLA images of the M87 jet at 2 centimeters journal May 1989
wsclean: an implementation of a fast, generic wide-field imager for radio astronomy journal August 2014
Dual differential polarimetry. A technique to recover polarimetric information from dual-polarization observations journal September 2016
Maximum Entropy Image Restoration in Astronomy journal September 1986
First M87 Event Horizon Telescope Results. III. Data Processing and Calibration journal April 2019
Discovery of Sub- to Superluminal Motions in the M87 Jet: An Implication of the Acceleration from Sub-relativistic to Relativistic Speeds text January 2013
Superresolution Interferometric Imaging with Sparse Modeling Using Total Squared Variation: Application to Imaging the Black Hole Shadow journal May 2018
Superresolution Full-polarimetric Imaging for Radio Interferometry with Sparse Modeling journal March 2017
Calibration of ALMA as a Phased Array. ALMA Observations During the 2017 VLBI Campaign journal May 2019
Discovery of sub- to Superluminal Motions in the m87 jet: an Implication of Acceleration from Sub-Relativistic to Relativistic Speeds journal December 2013
Radio structure of 3C147 determined by multi-element very long baseline interferometry journal October 1977
Restoring with Maximum Likelihood and Maximum Entropy* journal January 1972
Interferometric Monitoring of Gamma-ray Bright AGNs I: Results of Single-epoch Multifrequency Observations text January 2016
Calibration of ALMA as a phased array: ALMA observations during the 2017 VLBI campaign text January 2019
Dynamical Imaging with Interferometry journal November 2017
First M87 Event Horizon Telescope Results. V. Physical Origin of the Asymmetric Ring journal April 2019
Subluminal motion and limb brightening in the nuclear jet of M87 journal January 1989
Interferometric Imaging Directly with Closure Phases and Closure Amplitudes journal April 2018
A Phase Sensitive Interferometer Technique for the Measurement of the Fourier Transforms of Spatial Brightness Distributions of Small Angular Extent journal June 1958
The Next Generation Virgo Cluster Survey (NGVS). XVIII. Measurement and Calibration of Surface Brightness Fluctuation Distances for Bright Galaxies in Virgo (and Beyond) journal March 2018
A Multimass Velocity Dispersion Model of 47 Tucanae Indicates No Evidence for an Intermediate-mass Black Hole journal April 2019
Shock Waves and Energy Dissipation in Magnetohydrodynamic Turbulence journal April 2019
SPIRE Spectroscopy of Early-type Galaxies journal April 2019
Generalized Warped Disk Equations journal April 2019
High Gas Fraction in a CO-detected Main-sequence Galaxy at z > 3 journal April 2019

Cited By (65)

First M87 Event Horizon Telescope Results. V. Physical Origin of the Asymmetric Ring text January 2019
Standard Quantum Limit and Heisenberg Limit in Function Estimation journal January 2020
Approaching the black hole by numerical simulations text January 2019
ALMA Observations of the Terahertz Spectrum of Sagittarius A* journal August 2019
Black Hole Spin Signature in the Black Hole Shadow of M87 in the Flaring State journal June 2019
The Effects of Finite Distance on the Gravitational Deflection Angle of Light journal November 2019
The effects of finite distance on the gravitational deflection angle of light text January 2019
Lensing by Kerr black holes journal February 2020
Testing the Schwarzschild metric in a strong field region with the Event Horizon Telescope text January 2019
VLBI imaging of black holes via second moment regularization text January 2019
Orientation of the crescent image of M 87* journal February 2020
First M87 Event Horizon Telescope Results. VI. The Shadow and Mass of the Central Black Hole journal April 2019
Measurement of the spin of the M87 black hole from its observed twisted light text January 2019
Measurement of the spin of the M87 black hole from its observed twisted light text January 2019
Weak and strong deflection gravitational lensing by a renormalization group improved Schwarzschild black hole journal December 2019
Scale-invariance of black hole accretion: modelling emission from a black hole X-ray binary with relativistic accretion flow simulations journal November 2019
A 40 Billion Solar-mass Black Hole in the Extreme Core of Holm 15A, the Central Galaxy of Abell 85 journal December 2019
Resolving accretion flows in nearby active galactic nuclei with the Event Horizon Telescope journal October 2019
VLBI imaging of black holes via second moment regularization journal September 2019
Magnetically charged black holes from non-linear electrodynamics and the Event Horizon Telescope journal February 2020
Observational signature of a near-extremal Kerr-Sen black hole in the heterotic string theory text January 2019
Metrics and Motivations for Earth–Space VLBI: Time-resolving Sgr A* with the Event Horizon Telescope journal August 2019
Impact of a Spinning Supermassive Black Hole on the Orbit and Gravitational Waves of a Nearby Compact Binary text January 2019
Relativistic Jets from AGN Viewed at Highest Angular Resolution journal December 2019
Measurement of the spin of the M87 black hole from its observed twisted light journal November 2019
Modeling non-thermal emission from the jet-launching region of M 87 with adaptive mesh refinement journal November 2019
rPICARD: A CASA-based calibration pipeline for VLBI data: Calibration and imaging of 7 mm VLBA observations of the AGN jet in M 87 journal June 2019
The Shadow of a Spherically Accreting Black Hole journal November 2019
Resolving accretion flows in nearby active galactic nuclei with the Event Horizon Telescope text January 2019
Testing the Schwarzschild metric in a strong field region with the Event Horizon Telescope journal September 2019
Lensing by Kerr Black Holes text January 2019
Relativistic Aspects of Accreting Supermassive Black Hole Binaries in Their Natural Habitat: A Review journal May 2019
Photon emission near Myers-Perry black holes in the large dimension limit journal January 2020
Silhouette of M87*: A new window to peek into the world of hidden dimensions text January 2019
Observational signature of a near-extremal Kerr-Sen black hole in the heterotic string theory journal January 2020
The Shadow of a Spherically Accreting Black Hole text January 2019
Observability of spherical photon orbits in near-extremal Kerr black holes text January 2019
The Brightest Point in Accretion Disk and Black Hole Spin: Implication to the Image of Black Hole M87* journal August 2019
EHT-HOPS Pipeline for Millimeter VLBI Data Reduction journal August 2019
Asymptotic safety casts its shadow journal June 2019
Influence of geometrical configuration on low angular momentum relativistic accretion around rotating black holes journal August 2019
Kinematics of the M87 jet in the collimation zone: gradual acceleration and velocity stratification text January 2019
Orientation of the crescent image of M 87* text January 2019
Impact of a Spinning Supermassive Black Hole on the Orbit and Gravitational Waves of a Nearby Compact Binary journal December 2019
An environment for sustainable research software in Germany and beyond: current state, open challenges, and call for action journal January 2020
An environment for sustainable research software in Germany and beyond: current state, open challenges, and call for action journal January 2020
Standard Quantum Limit and Heisenberg Limit in Function Estimation text January 2018
EHT-HOPS pipeline for millimeter VLBI data reduction text January 2019
First M87 Event Horizon Telescope Results. III. Data Processing and Calibration journal April 2019
Approaching the Black Hole by Numerical Simulations journal April 2019
Anisotropic ultracompact Schwarzschild star by gravitational decoupling text January 2019
Metrics and Motivations for Earth-Space VLBI: Time-Resolving Sgr A* with the Event Horizon Telescope text January 2019
First M87 Event Horizon Telescope Results. V. Physical Origin of the Asymmetric Ring journal April 2019
Silhouette of M87*: A new window to peek into the world of hidden dimensions journal February 2020
Observability of spherical photon orbits in near-extremal Kerr black holes journal August 2019
Testing the rotational nature of the supermassive object M87* from the circularity and size of its first image journal August 2019
Rotating black holes with an anisotropic matter field journal March 2020
Kinematics of the M87 Jet in the Collimation Zone: Gradual Acceleration and Velocity Stratification journal December 2019
Kerr Black Holes within a Modified Theory of Gravity journal August 2019
Influence of the vacuum polarization effect on the motion of charged particles in the magnetic field around a Schwarzschild black hole journal October 2019
Prospects for Wideband VLBI Correlation in the Cloud journal October 2019
Higher order corrections to deflection angle of massive particles and light rays in plasma media for stationary spacetimes using the Gauss-Bonnet theorem journal November 2019
Anisotropic ultracompact Schwarzschild star by gravitational decoupling journal September 2019
Black Hole Spin Measurement Based on Time-domain VLBI Observations of Infalling Gas Clouds journal December 2019
Charged cosmological black holes: A thorough study of a family of solutions journal November 2019

Figures / Tables (52)

μas. Each point denotes a single scan, which range in duration from 4 to 7 minutes. Bottom panels: the full baseline coverage on M87 for each observation. In all panels, the dashed circles show baseline lengths corresponding to the indicated fringe spacings (0.2" for the upper-left panel; 25 and 50 μas for the remaining panels)." data-ostiid="1571628">
Figure 1(p. 7)figure Figure 1
Figure 2(p. 7)figure Figure 2
Figure 3(p. 8)figure Figure 3
Table 1(p. 9)table Table 1
Figure 4(p. 11)figure Figure 4
Table 2(p. 11)table Table 2
Figure 5(p. 12)figure Figure 5
Figure 6(p. 14)figure Figure 6
Figure 7(p. 15)figure Figure 7
Figure 8(p. 16)figure Figure 8
Figure 9(p. 16)figure Figure 9
Figure 10(p. 17)figure Figure 10
Table 3(p. 18)table Table 3
Figure 11(p. 19)figure Figure 11
Table 4(p. 19)table Table 4
Table 5(p. 20)table Table 5
Figure 12(p. 21)figure Figure 12
Figure 13(p. 21)figure Figure 13
Figure 14(p. 22)figure Figure 14
Figure 15(p. 22)figure Figure 15
Figure 16(p. 23)figure Figure 16
Figure 17(p. 24)figure Figure 17
Figure 18(p. 24)figure Figure 18
Figure 19(p. 25)figure Figure 19
Figure 20(p. 26)figure Figure 20
Figure 21(p. 26)figure Figure 21
Table 6(p. 26)table Table 6
Figure 22(p. 27)figure Figure 22
Figure 23(p. 27)figure Figure 23
Figure 24(p. 29)figure Figure 24
Table 7(p. 30)table Table 7
Figure 25(p. 31)figure Figure 25
Figure 26(p. 31)figure Figure 26
Figure 27(p. 31)figure Figure 27
Table 8(p. 36)table Table 8
Figure 28(p. 37)figure Figure 28
Figure 29(p. 37)figure Figure 29
Figure 30(p. 38)figure Figure 30
Table 9(p. 38)table Table 9
Table 10(p. 39)table Table 10
Table 11(p. 39)table Table 11
Figure 31(p. 40)figure Figure 31
Table 12(p. 41)table Table 12
Table 13(p. 41)table Table 13
Figure 32(p. 42)figure Figure 32
Figure 33(p. 43)figure Figure 33
Figure 34(p. 44)figure Figure 34
Table 14(p. 45)table Table 14
Figure 35(p. 46)figure Figure 35
Figure 36(p. 47)figure Figure 36
Figure 37(p. 48)figure Figure 37
Figure 38(p. 48)figure Figure 38