First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole
Journal article, 2019

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 similar to 40 mu as, 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.

techniques: image processing

techniques: interferometric

galaxies: individual (M87)

galaxies: jets

techniques: high angular resolution

black hole physics

Author

Kazunori Akiyama

National Radio Astronomy Observatory

Harvard University

Massachusetts Institute of Technology (MIT)

National Astronomical Observatory of Japan

Antxon Alberdi

Spanish National Research Council (CSIC)

Walter Alef

Max Planck Society

Keiichi Asada

Academia Sinica

Rebecca Azulay

Max Planck Society

Universitat de Valencia

Anne-Kathrin Baczko

Max Planck Society

David Ball

University of Arizona

Mislav Balokovic

Harvard-Smithsonian Center for Astrophysics

Harvard University

John Barrett

Massachusetts Institute of Technology (MIT)

Dan Bintley

East Asian Observatory

Lindy Blackburn

Harvard-Smithsonian Center for Astrophysics

Harvard University

Wilfred Boland

Nederlandse Onderzoekschool voor Astronomie (NOVA)

Katherine L. Bouman

Harvard-Smithsonian Center for Astrophysics

Harvard University

California Institute of Technology (Caltech)

Geoffrey C. Bower

Academia Sinica

Michael Bremer

Institut de RadioAstronomie Millimetrique (IRAM)

Christiaan D. Brinkerink

Radboud University

Roger Brissenden

Harvard-Smithsonian Center for Astrophysics

Harvard University

Silke Britzen

Max Planck Society

Avery E. Broderick

University of Waterloo

Perimeter Institute for Theoretical Physics

Dominique Broguiere

Institut de RadioAstronomie Millimetrique (IRAM)

Thomas Bronzwaer

Radboud University

Do-Young Byun

University of Science and Technology (UST)

Korea Astronomy and Space Science Institute

John E. Carlstrom

University of Chicago

Andrew Chael

Harvard-Smithsonian Center for Astrophysics

Harvard University

Chi-Kwan Chan

University of Arizona

Shami Chatterjee

Cornell University

Koushik Chatterjee

University of Amsterdam

Ming-Tang Chen

Academia Sinica

Yongjun Chen

Chinese Academy of Sciences

Ilje Cho

University of Science and Technology (UST)

Korea Astronomy and Space Science Institute

Pierre Christian

University of Arizona

Harvard-Smithsonian Center for Astrophysics

John Conway

Chalmers, Space, Earth and Environment, Onsala Space Observatory

Onsala Space Observatory

James M. Cordes

Cornell University

Geoffrey B. Crew

Massachusetts Institute of Technology (MIT)

Yuzhu Cui

The Graduate University for Advanced Studies (SOKENDAI)

National Astronomical Observatory of Japan

Jordy Davelaar

Radboud University

Mariafelicia De Laurentis

Compl Univ Monte S Angelo

Goethe University Frankfurt

Universita degli Studi di Napoli Federico II

Roger Deane

Rhodes University

University of Pretoria

Jessica Dempsey

East Asian Observatory

Gregory Desvignes

Max Planck Society

Jason Dexter

Max Planck Society

Sheperd S. Doeleman

Harvard University

Harvard-Smithsonian Center for Astrophysics

Ralph P. Eatough

Max Planck Society

Heino Falcke

Radboud University

Vincent L. Fish

Massachusetts Institute of Technology (MIT)

Ed Fomalont

National Radio Astronomy Observatory

Raquel Fraga-Encinas

Radboud University

William T. Freeman

Google Inc.

Massachusetts Institute of Technology (MIT)

Per Friberg

East Asian Observatory

Christian M. Fromm

Goethe University Frankfurt

Jose L. Gomez

Spanish National Research Council (CSIC)

Peter Galison

Harvard University

Charles F. Gammie

University of Illinois

Roberto Garcia

Institut de RadioAstronomie Millimetrique (IRAM)

Olivier Gentaz

Institut de RadioAstronomie Millimetrique (IRAM)

Boris Georgiev

University of Waterloo

Ciriaco Goddi

Leiden University

Radboud University

Roman Gold

Goethe University Frankfurt

Minfeng Gu

Chinese Academy of Sciences

Mark Gurwell

Harvard-Smithsonian Center for Astrophysics

Kazuhiro Hada

National Astronomical Observatory of Japan

The Graduate University for Advanced Studies (SOKENDAI)

Michael H. Hecht

Massachusetts Institute of Technology (MIT)

Ronald Hesper

University of Groningen

Luis C. Ho

Beijing University of Technology

Paul Ho

Academia Sinica

Mareki Honma

National Astronomical Observatory of Japan

The Graduate University for Advanced Studies (SOKENDAI)

Chih-Wei L. Huang

Academia Sinica

Lei Huang

Chinese Academy of Sciences

David H. Hughes

National Institute of Astrophysics, Optics and Electronics

Shiro Ikeda

National Astronomical Observatory of Japan

The Institute of Statistical Mathematics

University of Tokyo

The Graduate University for Advanced Studies (SOKENDAI)

Makoto Inoue

Academia Sinica

Sara Issaoun

Radboud University

David J. James

Harvard-Smithsonian Center for Astrophysics

Harvard University

Michael Janssen

Radboud University

Britton Jeter

University of Waterloo

Wu Jiang

Chinese Academy of Sciences

Michael D. Johnson

Harvard University

Harvard-Smithsonian Center for Astrophysics

Svetlana Jorstad

Saint Petersburg State University - Spsu

Boston University

Taehyun Jung

Korea Astronomy and Space Science Institute

Mansour Karami

University of Waterloo

Perimeter Institute for Theoretical Physics

Ramesh Karuppusamy

Max Planck Society

Tomohisa Kawashima

National Astronomical Observatory of Japan

Garrett K. Keating

Harvard-Smithsonian Center for Astrophysics

Mark Kettenis

Joint Institute for VLBI in Europe (JIVE)

Jae-Young Kim

Max Planck Society

Junhan Kim

University of Arizona

Jongsoo Kim

Korea Astronomy and Space Science Institute

Motoki Kino

National Astronomical Observatory of Japan

Kogakuin University of Technology and Engineering

Jun Yi Koay

Academia Sinica

Patrick M. Koch

Academia Sinica

Shoko Koyama

Academia Sinica

Michael Kramer

Max Planck Society

Carsten Kramer

Institut de RadioAstronomie Millimetrique (IRAM)

Thomas P. Krichbaum

Max Planck Society

Cheng-Yu Kuo

National Sun Yat-Sen University Taiwan

Tod R. Lauer

National Optical Astronomy Observatory

Sang-Sung Lee

Korea Astronomy and Space Science Institute

Yan-Rong Li

Chinese Academy of Sciences

Zhiyuan Li

Nanjing University

Michael Lindqvist

Chalmers, Space, Earth and Environment, Onsala Space Observatory, Onsala Space Observatory, Observation Support

Onsala Space Observatory

Kuo Liu

Max Planck Society

Elisabetta Liuzzo

Italian ALMA Reg Ctr

Wen-Ping Lo

National Taiwan University

Academia Sinica

Andrei P. Lobanov

Max Planck Society

Laurent Loinard

Universidad Nacional Autonoma de Mexico

Colin Lonsdale

Massachusetts Institute of Technology (MIT)

Ru-Sen Lu

Chinese Academy of Sciences

Max Planck Society

Nicholas R. MacDonald

Max Planck Society

Jirong Mao

Chinese Academy of Sciences

Sera Markoff

University of Amsterdam

Daniel P. Marrone

University of Arizona

Alan P. Marscher

Boston University

Ivan Marti-Vidal

Chalmers, Space, Earth and Environment, Onsala Space Observatory

Onsala Space Observatory

Satoki Matsushita

Academia Sinica

Lynn D. Matthews

Massachusetts Institute of Technology (MIT)

Lia Medeiros

University of Arizona

University of California at Santa Barbara

Karl M. Menten

Max Planck Society

Yosuke Mizuno

Goethe University Frankfurt

Izumi Mizuno

East Asian Observatory

James M. Moran

Harvard-Smithsonian Center for Astrophysics

Harvard University

Kotaro Moriyama

Massachusetts Institute of Technology (MIT)

Monika Moscibrodzka

Radboud University

Cornelia Mueller

Radboud University

Max Planck Society

Hiroshi Nagai

National Astronomical Observatory of Japan

The Graduate University for Advanced Studies (SOKENDAI)

Neil M. Nagar

University of Concepcion

Masanori Nakamura

Academia Sinica

Ramesh Narayan

Harvard University

Harvard-Smithsonian Center for Astrophysics

Gopal Narayanan

University of Massachusetts

Iniyan Natarajan

Rhodes University

Roberto Neri

Institut de RadioAstronomie Millimetrique (IRAM)

Chunchong Ni

University of Waterloo

Aristeidis Noutsos

Max Planck Society

Hiroki Okino

University of Tokyo

Hector Olivares

Goethe University Frankfurt

Feryal Ozel

University of Arizona

Daniel C. M. Palumbo

Harvard-Smithsonian Center for Astrophysics

Harvard University

Nimesh Patel

Harvard-Smithsonian Center for Astrophysics

Ue-Li Pen

Canadian Institute for Advanced Research

University of Toronto

Perimeter Institute for Theoretical Physics

Dominic W. Pesce

Harvard University

Harvard-Smithsonian Center for Astrophysics

Vincent Pietu

Institut de RadioAstronomie Millimetrique (IRAM)

Richard Plambeck

University of California at Berkeley

Aleksandar PopStefanija

University of Massachusetts

Oliver Porth

Goethe University Frankfurt

University of Amsterdam

Ben Prather

University of Illinois

Jorge A. Preciado-Lopez

Perimeter Institute for Theoretical Physics

Dimitrios Psaltis

University of Arizona

Hung-Yi Pu

Perimeter Institute for Theoretical Physics

Venkatessh Ramakrishnan

University of Concepcion

Ramprasad Rao

Academia Sinica

Mark G. Rawlings

East Asian Observatory

Alexander W. Raymond

Harvard-Smithsonian Center for Astrophysics

Harvard University

Luciano Rezzolla

Goethe University Frankfurt

Bart Ripperda

Goethe University Frankfurt

Freek Roelofs

Radboud University

Alan Rogers

Massachusetts Institute of Technology (MIT)

University of Science and Technology (UST)

University of Waterloo

East Asian Observatory

Eduardo Ros

Max Planck Society

Mel Rose

University of Arizona

Arash Roshanineshat

University of Arizona

Helge Rottmann

Max Planck Society

Alan L. Roy

Max Planck Society

Chet Ruszczyk

Massachusetts Institute of Technology (MIT)

Benjamin R. Ryan

Los Alamos National Laboratory

Kazi L. J. Rygl

Italian ALMA Reg Ctr

Salvador Sanchez

Institut de RadioAstronomie Millimetrique (IRAM)

David Sanchez-Arguelles

Consejo Nacl Ciencia & Technol

National Institute of Astrophysics, Optics and Electronics

Mahito Sasada

Hiroshima University

Tuomas Savolainen

Max Planck Society

Aalto University

F. Peter Schloerb

University of Massachusetts

Karl-Friedrich Schuster

Institut de RadioAstronomie Millimetrique (IRAM)

Lijing Shao

Beijing University of Technology

Max Planck Society

Zhiqiang Shen

University of Amsterdam

Chinese Academy of Sciences

Des Small

Joint Institute for VLBI in Europe (JIVE)

Bong Won Sohn

University of Science and Technology (UST)

Yonsei University

Korea Astronomy and Space Science Institute

Jason SooHoo

Massachusetts Institute of Technology (MIT)

Fumie Tazaki

Chinese Academy of Sciences

Paul Tiede

Perimeter Institute for Theoretical Physics

University of Waterloo

Remo P. J. Tilanus

Netherlands Organisation for Scientific Research (NWO)

Radboud University

Leiden University

Michael Titus

Massachusetts Institute of Technology (MIT)

Kenji Toma

Tohoku University

Pablo Torne

Institut de RadioAstronomie Millimetrique (IRAM)

Max Planck Society

Tyler Trent

University of Arizona

Sascha Trippe

Seoul National University

Ilse van Bemmel

Joint Institute for VLBI in Europe (JIVE)

Huib Jan van Langevelde

Joint Institute for VLBI in Europe (JIVE)

Leiden University

Daniel R. van Rossum

Radboud University

Jan Wagner

Max Planck Society

John Wardle

Brandeis University

Jonathan Weintroub

Harvard-Smithsonian Center for Astrophysics

Harvard University

Norbert Wex

Max Planck Society

Robert Wharton

Max Planck Society

Maciek Wielgus

Harvard University

Harvard-Smithsonian Center for Astrophysics

George N. Wong

University of Illinois

Qingwen Wu

Huazhong University of Science and Technology

Andre Young

Radboud University

Ken Young

Harvard-Smithsonian Center for Astrophysics

Ziri Younsi

University College London (UCL)

Goethe University Frankfurt

Feng Yuan

Chinese Academy of Sciences

Ye-Fei Yuan

University of Science and Technology of China

J. Anton Zensus

Max Planck Society

Guangyao Zhao

Korea Astronomy and Space Science Institute

Shan-Shan Zhao

Radboud University

Nanjing University

Ziyan Zhu

Harvard University

Joseph R. Farah

Harvard-Smithsonian Center for Astrophysics

Harvard University

University of Massachusetts Boston

Zheng Meyer-Zhao

Academia Sinica

Netherlands Institute for Radio Astronomy (ASTRON)

Daniel Michalik

European Space Research and Technology Centre (ESA ESTEC)

University of Chicago

Andrew Nadolski

University of Illinois

Hiroaki Nishioka

Academia Sinica

Nicolas Pradel

Academia Sinica

Rurik A. Primiani

Systems & Technology Research

Kamal Souccar

University of Massachusetts

Laura Vertatschitsch

Systems & Technology Research

Harvard-Smithsonian Center for Astrophysics

Paul Yamaguchi

Harvard-Smithsonian Center for Astrophysics

Astrophysical Journal Letters

2041-8205 (ISSN) 2041-8213 (eISSN)

Vol. 875 1 L4

Subject Categories

Radiology, Nuclear Medicine and Medical Imaging

Computer Vision and Robotics (Autonomous Systems)

Medical Image Processing

DOI

10.3847/2041-8213/ab0e85

More information

Latest update

10/16/2019