The persistent shadow of the supermassive black hole of M 87: I. Observations, calibration, imaging, and analysis*
Journal article, 2024
In April 2019, the Event Horizon Telescope (EHT) Collaboration reported the first-ever event-horizon-scale images of a black hole, resolving the central compact radio source in the giant elliptical galaxy M 87. These images reveal a ring with a southerly brightness distribution and a diameter of ∼42 μas, consistent with the predicted size and shape of a shadow produced by the gravitationally lensed emission around a supermassive black hole. These results were obtained as part of the April 2017 EHT observation campaign, using a global very long baseline interferometric radio array operating at a wavelength of 1.3 mm. Here, we present results based on the second EHT observing campaign, taking place in April 2018 with an improved array, wider frequency coverage, and increased bandwidth. In particular, the additional baselines provided by the Greenland telescope improved the coverage of the array. Multiyear EHT observations provide independent snapshots of the horizon-scale emission, allowing us to confirm the persistence, size, and shape of the black hole shadow, and constrain the intrinsic structural variability of the accretion flow. We have confirmed the presence of an asymmetric ring structure, brighter in the southwest, with a median diameter of 43.3-3.1+1.5 μas. The diameter of the 2018 ring is remarkably consistent with the diameter obtained from the previous 2017 observations. On the other hand, the position angle of the brightness asymmetry in 2018 is shifted by about 30 relative to 2017. The perennial persistence of the ring and its diameter robustly support the interpretation that the ring is formed by lensed emission surrounding a Kerr black hole with a mass ∼6.5× 109M. The significant change in the ring brightness asymmetry implies a spin axis that is more consistent with the position angle of the large-scale jet.
Black hole physics
Galaxies: active
Galaxies: individual: M 87
Gravitation
Accretion, accretion disks
Galaxies: jets
Author
Kazunori Akiyama
Massachusetts Institute of Technology (MIT)
Antxon Alberdi
Institute of Astrophysics of Andalusia (IAA)
Walter Alef
Max Planck Society
Juan-Carlos Algaba
University of Malaya
Richard Anantua
Harvard University
Richard Anantua
Academia Sinica
R. Azulay
Max Planck Society
U. Bach
Max Planck Society
A. K. Baczko
Max Planck Society
David Ball
University of Arizona
Mislav Baloković
Yale University
Bidisha Bandyopadhyay
University of Concepcion
John Barrett
Massachusetts Institute of Technology (MIT)
M. Bauböck
University of Illinois
Bradford A. Benson
Fermi National Accelerator Laboratory
Dan Bintley
East Asian Observatory
Lindy Blackburn
Harvard University
R. Blundell
Harvard-Smithsonian Center for Astrophysics
K. L. Bouman
California Institute of Technology (Caltech)
G. C. Bower
Academia Sinica
Hope Boyce
McGill University
Michael Bremer
Institut de Radioastronomie Millimétrique (IRAM)
Roger Brissenden
Harvard University
Silke Britzen
Max Planck Society
Avery E. Broderick
Perimeter Institute for Theoretical Physics
D. Broguière
Institut de Radioastronomie Millimétrique (IRAM)
Thomas Bronzwaer
Radboud University
Sandra Bustamente
University of Massachusetts
J. E. Carlstrom
University of Chicago
A. Chael
Princeton University
Do Young Byun
University of Arizona
Dominic O. Chang
Harvard University
Chiara Ceccobello
Harvard University
S. Chatterjee
Cornell University
Ming Tang Chen
Academia Sinica
Yongjun Chen
Shanghai Astronomical Observatory
X. P. Cheng
Korea Astronomy and Space Science Institute
I. Cho
Institute of Astrophysics of Andalusia (IAA)
Pierre Christian
Fairfield University
Nicholas S. Conroy
Harvard-Smithsonian Center for Astrophysics
John Conway
Chalmers, Space, Earth and Environment, Onsala Space Observatory
Thomas M. Crawford
University of Chicago
G. Crew
Massachusetts Institute of Technology (MIT)
Alejandro Cruz-Osorio
Universidad Nacional Autónoma de México
Yuzhu Cui
Massachusetts Institute of Technology (MIT)
Rohan Dahale
Institute of Astrophysics of Andalusia (IAA)
Jordy Davelaar
Radboud University
Mariafelicia De Laurentis
University of Naples Federico II
R. P. Deane
University of Witwatersrand
Rohan Dahale
East Asian Observatory
Gregory Desvignes
Max Planck Society
Jason Dexter
JILA
Vedant Dhruv
University of Illinois
Indu K. Dihingia
Shanghai Jiao Tong University
S. Doeleman
Harvard University
Sergio A. Dzib
Max Planck Society
Ralph P. Eatough
Max Planck Society
Razieh Emami
Harvard-Smithsonian Center for Astrophysics
H.D. Falcke
National Astronomical Observatory of Japan
Joseph R. Farah
Las Cumbres Observatory Global Telescope Network
V. Fish
Massachusetts Institute of Technology (MIT)
E. Fomalont
National Radio Astronomy Observatory
H.D. Falcke
University of Arizona
Marianna Foschi
Institute of Astrophysics of Andalusia (IAA)
R. Fraga-Encinas
Radboud University
William T. Freeman
Massachusetts Institute of Technology
E. Fomalont
East Asian Observatory
Christian M. Fromm
Max Planck Society
Antonio Fuentes
Institute of Astrophysics of Andalusia (IAA)
Peter Galison
Harvard University
Charles F. Gammie
University of Illinois
Roberto Garcia
Institut de Radioastronomie Millimétrique (IRAM)
Olivier Gentaz
Institut de Radioastronomie Millimétrique (IRAM)
Boris Georgiev
University of Arizona
C. Goddi
University of Sao Paulo (USP)
R. Gold
University of Southern Denmark
Arturo I. Gómez-Ruiz
National Institute of Astrophysics, Optics and Electronics
José L. Gómez
Institute of Astrophysics of Andalusia (IAA)
Minfeng Gu
Shanghai Astronomical Observatory
M. Gurwell
Harvard-Smithsonian Center for Astrophysics
K. Hada
National Astronomical Observatory of Japan
Daryl Haggard
McGill University
R. Hesper
University of Groningen
Dirk Heumann
University of Arizona
Luis C. Ho
Beijing University of Technology
P. T. P. Ho
Academia Sinica
Mareki Honma
National Astronomical Observatory of Japan
Chih Wei L. Huang
Academia Sinica
Lei Huang
Shanghai Astronomical Observatory
David H. Hughes
National Institute of Astrophysics, Optics and Electronics
Shiro Ikeda
National Astronomical Observatory of Japan
C.M. Violette Impellizzeri
National Radio Astronomy Observatory
Makoto Inoue
Academia Sinica
S. Issaoun
Harvard-Smithsonian Center for Astrophysics
David J. James
ASTRAVEO
Buell T. Jannuzi
University of Arizona
Lei Huang
Max Planck Society
Britton Jeter
Academia Sinica
Wu Jiang
Shanghai Astronomical Observatory
Alejandra Jimenez-Rosales
Radboud University
Makoto Inoue
Harvard University
S.G. Jorstad
Boston University
Adam C. Jones
University of Chicago
Abhishek V. Joshi
University of Illinois
Taehyun Jung
Korea Astronomy and Space Science Institute
R. Karuppusamy
Max Planck Society
Tomohisa Kawashima
University of Tokyo
G. Keating
Harvard-Smithsonian Center for Astrophysics
M. M. Kettenis
Joint Institute for VLBI in Europe (JIVE)
Dong-Jin Kim
Massachusetts Institute of Technology (MIT)
Jae-Young Kim
Max Planck Society
Taehyun Jung
Korea Astronomy and Space Science Institute
Junhan Kim
Korea Advanced Institute of Science and Technology (KAIST)
R. Karuppusamy
National Astronomical Observatory of Japan
Jun Yi Koay
Academia Sinica
Prashant Kocherlakota
Goethe University Frankfurt
Yutaro Kofuji
National Astronomical Observatory of Japan
M. M. Kettenis
Academia Sinica
Shoko Koyama
Academia Sinica
Jae-Young Kim
Institut de Radioastronomie Millimétrique (IRAM)
Joana A. Kramer
Max Planck Society
M. Kramer
Max Planck Society
T.P. Krichbaum
Max Planck Society
Greg Lindahl
Academia Sinica
Noemi La Bella
Radboud University
Sang Sung Lee
Korea Astronomy and Space Science Institute
Aviad Levis
California Institute of Technology (Caltech)
Zhiyuan Li
Nanjing University
R. Lico
Institute of Astrophysics of Andalusia (IAA)
Greg Lindahl
Harvard-Smithsonian Center for Astrophysics
Michael Lindqvist
Chalmers, Space, Earth and Environment, Onsala Space Observatory
Mikhail Lisakov
Max Planck Society
Jun Liu
Max Planck Society
Kuo Liu
Max Planck Society
Elisabetta Liuzzo
Istituto di Radioastronomia
Wen-Ping Lo
Academia Sinica
A. P. Lobanov
Max Planck Society
L. Loinard
Universidad Nacional Autónoma de México
Greg Lindahl
Massachusetts Institute of Technology (MIT)
Amy E. Lowitz
University of Arizona
R.S. Lu
Max Planck Society
N. R. Macdonald
Max Planck Society
Jirong Mao
Yunnan Observatories
Nicola Marchili
Max Planck Society
S. Markoff
Anton Pannekoek Institute for Astronomy
D. P. Marrone
University of Arizona
A. Marscher
Boston University
Ivan Marti-Vidal
Universitat de Valencia
Amy E. Lowitz
Academia Sinica
Lynn D. Matthews
Massachusetts Institute of Technology (MIT)
Lia Medeiros
Princeton University
K. Menten
Max Planck Society
Izumi Mizuno
East Asian Observatory
Yosuke Mizuno
Goethe University Frankfurt
Joshua Montgomery
University of Chicago
James M. Moran
Harvard University
Kotaro Moriyama
Goethe University Frankfurt
M. Mościbrodzka
Radboud University
Wanga Mulaudzi
Anton Pannekoek Institute for Astronomy
C. Müller
Max Planck Society
Hendrik Müller
Max Planck Society
A. Mus
Universitat de Valencia
Gibwa Musoke
Radboud University
I. Myserlis
Institut de Radioastronomie Millimétrique (IRAM)
H. Nagai
National Astronomical Observatory of Japan
N. M. Nagar
University of Concepcion
Lia Medeiros
Academia Sinica
Daniel Michalik
University of Massachusetts
Iniyan Natarajan
Harvard University
Antonios Nathanail
Goethe University Frankfurt
Santiago Navarro Fuentes
Institut de Radioastronomie Millimétrique (IRAM)
Joseph Neilsen
Villanova University
Chunchong Ni
Perimeter Institute for Theoretical Physics
M.A. Nowak
Washington University in St. Louis
Junghwan Oh
Joint Institute for VLBI in Europe (JIVE)
Hiroki Okino
National Astronomical Observatory of Japan
Héctor Olivares
Radboud University
Tomoaki Oyama
National Astronomical Observatory of Japan
Feryal Özel
Georgia Institute of Technology
N. Patel
Harvard University
Georgios Filippos Paraschos
Max Planck Society
Jongho Park
Kyung Hee University
Harriet Parsons
East Asian Observatory
N. Patel
Harvard-Smithsonian Center for Astrophysics
U. L. Pen
Academia Sinica
Dominic W. Pesce
Harvard University
Vincent Piétu
Institut de Radioastronomie Millimétrique (IRAM)
Aleksandar PopStefanija
University of Massachusetts
Oliver Porth
Goethe University Frankfurt
Ben Prather
University of Illinois
Venkatessh Ramakrishnan
Georgia Institute of Technology
R. Rao
Academia Sinica
Venkatessh Ramakrishnan
University of Concepcion
R. Rao
Harvard-Smithsonian Center for Astrophysics
M.G. Rawlings
East Asian Observatory
Alexander W. Raymond
Harvard University
Luciano Rezzolla
Goethe University Frankfurt
Angelo Ricarte
Harvard University
Bart Ripperda
Perimeter Institute for Theoretical Physics
F. Roelofs
Harvard University
C. Romero-Cañizales
Academia Sinica
Eduardo Ros
Max Planck Society
Arash Roshanineshat
University of Arizona
H. Rottmann
Max Planck Society
A. Roy
Max Planck Society
Ignacio Ruiz
Institut de Radioastronomie Millimétrique (IRAM)
C. Ruszczyk
Massachusetts Institute of Technology (MIT)
Kazi L.J. Rygl
Istituto di Radioastronomia
S. Sanchez
Institut de Radioastronomie Millimétrique (IRAM)
David Sánchez-Arguelles
National Institute of Astrophysics, Optics and Electronics
M. Sánchez Portal
Institut de Radioastronomie Millimétrique (IRAM)
Mahito Sasada
National Astronomical Observatory of Japan
Kaushik Satapathy
University of Arizona
T. Savolainen
Max Planck Society
F. P. Schloerb
University of Massachusetts
Jonathan Schonfeld
Harvard-Smithsonian Center for Astrophysics
K. Schuster
Institut de Radioastronomie Millimétrique (IRAM)
Lijing Shao
Max Planck Society
Zhi Qiang Shen
Shanghai Astronomical Observatory
Des Small
Joint Institute for VLBI in Europe (JIVE)
Bong Won Sohn
Korea Astronomy and Space Science Institute
J. SooHoo
Massachusetts Institute of Technology (MIT)
León David Sosapanta Salas
Anton Pannekoek Institute for Astronomy
Kamal Souccar
University of Massachusetts
Joshua S. Stanway
University of Central Lancashire
He Sun
Beijing University of Technology
Fumie Tazaki
Tokyo Electron Technology Solutions Limited
Alexandra J. Tetarenko
University of Lethbridge
Paul Tiede
Harvard University
R. P. J. Tilanus
University of Arizona
M. Titus
Massachusetts Institute of Technology (MIT)
Kenji Toma
Tohoku University
Pablo Torne
Max Planck Society
Teresa Toscano
Institute of Astrophysics of Andalusia (IAA)
E. Traianou
Institute of Astrophysics of Andalusia (IAA)
Tyler Trent
University of Arizona
S. Trippe
Seoul National University
Matthew Turk
University of Illinois
I. van Bemmel
Joint Institute for VLBI in Europe (JIVE)
H. J. van Langevelde
Leiden University
Daniel R. van Rossum
Radboud University
Jesse Vos
Radboud University
Jan Wagner
Max Planck Society
D. Ward-Thompson
University of Central Lancashire
John Wardle
Brandeis University
Jasmin E. Washington
University of Arizona
J. Weintroub
Harvard University
Robert Wharton
Max Planck Society
M. Wielgus
Max Planck Society
K. Wiik
Tuorla Observatory
Gunther Witzel
Max Planck Society
Michael F. Wondrak
Radboud University
George N. Wong
Princeton University
Qingwen Wu
Huazhong University of Science and Technology
Nitika Yadlapalli
California Institute of Technology (Caltech)
Paul Yamaguchi
Harvard-Smithsonian Center for Astrophysics
Aristomenis Yfantis
Radboud University
Doosoo Yoon
Anton Pannekoek Institute for Astronomy
A. Young
Radboud University
Ziri Younsi
Goethe University Frankfurt
Wei Yu
Harvard-Smithsonian Center for Astrophysics
Feng Yuan
Shanghai Astronomical Observatory
Ye-Fei Yuan
University of Science and Technology of China
A.J. Zensus
Max Planck Society
Shuo Zhang
Michigan State University
G. Y. Zhao
Institute of Astrophysics of Andalusia (IAA)
Shan-Shan Zhao
Shanghai Astronomical Observatory
Alexander Allardi
University of Vermont
Shu-Hao Chang
Academia Sinica
Chih-Cheng Chang
Academia Sinica
Song-Chu Chang
National Chung-Shan Institute of Science and Technology
Chung-Chen Chen
Academia Sinica
R. Chilson
Academia Sinica
Aaron Faber
Western University
David M. Gale
National Institute of Astrophysics, Optics and Electronics
Chih-Chiang Han
Academia Sinica
Kuo-Chang Han
National Chung-Shan Institute of Science and Technology
Yutaka Hasegawa
Osaka Metropolitan University
José Luis Hernández-Rebollar
National Institute of Astrophysics, Optics and Electronics
Yau-De Huang
Academia Sinica
Homin Jiang
Academia Sinica
Hao Jinchi
National Chung-Shan Institute of Science and Technology
Kimihiro Kimura
JAXA Institute of Space and Astronautical Science
Derek Kubo
Academia Sinica
Chao-Te Li
Academia Sinica
Lupin C.-C. Lin
Academia Sinica
Ching-Tang Liu
Academia Sinica
Kuan-Yu Liu
Academia Sinica
Li-Ming Lu
National Chung-Shan Institute of Science and Technology
Pierre L. Martin-Cocher
Academia Sinica
Z. Meyer-Zhao
Academia Sinica
Alfredo Montaña
National Institute of Astrophysics, Optics and Electronics
Anthony Moraghan
Academia Sinica
Marcos Emir Moreno-Nolasco
Coorporacion Mexicana de Investigacion en Materiales S.A. de C.V. Ciencia y Tecnologia 790
Hiroaki Nishioka
Academia Sinica
Timothy Norton
Harvard-Smithsonian Center for Astrophysics
George Nystrom
Academia Sinica
Hideo Ogawa
Osaka Metropolitan University
Peter Oshiro
Academia Sinica
N. Pradel
Academia Sinica
G. Principe
Istituto di Radioastronomia
Philippe A. Raffin
Academia Sinica
Iván Rodríguez-Montoya
National Institute of Astrophysics, Optics and Electronics
Paul Shaw
Academia Sinica
William Snow
Academia Sinica
Tirupati K. Sridharan
Harvard-Smithsonian Center for Astrophysics
Ranjani Srinivasan
Harvard-Smithsonian Center for Astrophysics
Ta-Shun Wei
Academia Sinica
Chen-Yu Yu
Academia Sinica
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 681 A79Subject Categories
Physical Sciences
Earth and Related Environmental Sciences
DOI
10.1051/0004-6361/202347932