First Sagittarius A* Event Horizon Telescope Results. IV. Variability, Morphology, and Black Hole Mass
Journal article, 2022
In this paper we quantify the temporal variability and image morphology of the horizon-scale emission from Sgr A*, as observed by the EHT in 2017 April at a wavelength of 1.3 mm. We find that the Sgr A* data exhibit variability that exceeds what can be explained by the uncertainties in the data or by the effects of interstellar scattering. The magnitude of this variability can be a substantial fraction of the correlated flux density, reaching similar to 100% on some baselines. Through an exploration of simple geometric source models, we demonstrate that ring-like morphologies provide better fits to the Sgr A* data than do other morphologies with comparable complexity. We develop two strategies for fitting static geometric ring models to the time-variable Sgr A* data; one strategy fits models to short segments of data over which the source is static and averages these independent fits, while the other fits models to the full data set using a parametric model for the structural variability power spectrum around the average source structure. Both geometric modeling and image-domain feature extraction techniques determine the ring diameter to be 51.8 +/- 2.3 mu as (68% credible intervals), with the ring thickness constrained to have an FWHM between similar to 30% and 50% of the ring diameter. To bring the diameter measurements to a common physical scale, we calibrate them using synthetic data generated from GRMHD simulations. This calibration constrains the angular size of the gravitational radius to be 4.8(-0.7)(+1.4) mu as, which we combine with an independent distance measurement from maser parallaxes to determine the mass of Sgr A* to be 4.0(-0.6)(+1.1) x 10(6) M-circle dot.
Author
Kazunori Akiyama
Harvard University
Massachusetts Institute of Technology (MIT)
National Astronomical Observatory of Japan
Antxon Alberdi
Spanish National Research Council (CSIC)
Walter Alef
Max Planck Society
Juan Carlos Algaba
University of Malaya
Richard Anantua
Harvard University
University of Texas at San Antonio
Harvard-Smithsonian Center for Astrophysics
Keiichi Asada
Academia Sinica
Rebecca Azulay
Universitat de Valencia
Max Planck Society
Uwe Bach
Max Planck Society
Anne-Kathrin Baczko
Max Planck Society
David Ball
University of Arizona
Mislav Balokovic
Yale University
John Barrett
Massachusetts Institute of Technology (MIT)
Michi Baubock
University of Illinois
Bradford A. Benson
Fermi National Accelerator Laboratory
University of Chicago
Dan Bintley
East Asian Observatory
James Clerk Maxwell Telescope
Lindy Blackburn
Harvard-Smithsonian Center for Astrophysics
Harvard University
Raymond Blundell
Harvard-Smithsonian Center for Astrophysics
Katherine L. Bouman
California Institute of Technology (Caltech)
Geoffrey C. Bower
University of Hawaii
Academia Sinica
Hope Boyce
McGill University
Michael Bremer
Institut de Radioastronomie Millimétrique (IRAM)
Christiaan D. Brinkerink
Radboud University
Roger Brissenden
Harvard University
Harvard-Smithsonian Center for Astrophysics
Silke Britzen
Max Planck Society
Avery E. Broderick
Perimeter Institute for Theoretical Physics
University of Waterloo
Dominique Broguiere
Institut de Radioastronomie Millimétrique (IRAM)
Thomas Bronzwaer
Radboud University
Sandra Bustamante
University of Massachusetts
Do-Young Byun
Korea Astronomy and Space Science Institute
University of Science and Technology (UST)
John E. Carlstrom
University of Chicago
Chiara Ceccobello
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Andrew Chael
NASA Hubble Fellowship Program
Princeton University
Chi-kwan Chan
University of Arizona
Koushik Chatterjee
Harvard-Smithsonian Center for Astrophysics
Harvard University
Shami Chatterjee
Cornell University
Ming-Tang Chen
Academia Sinica
Yongjun Chen
Chinese Academy of Sciences
Xiaopeng Cheng
Korea Astronomy and Space Science Institute
Ilje Cho
Spanish National Research Council (CSIC)
Pierre Christian
Fairfield University
Nicholas S. Conroy
Harvard-Smithsonian Center for Astrophysics
University of Illinois
John Conway
Chalmers, Space, Earth and Environment, Onsala Space Observatory
James M. Cordes
Cornell University
Thomas M. Crawford
University of Chicago
Geoffrey B. Crew
Massachusetts Institute of Technology (MIT)
Alejandro Cruz-Osorio
Goethe University Frankfurt
Yuzhu Cui
Shanghai Jiao Tong University
The Graduate University for Advanced Studies (SOKENDAI)
National Astronomical Observatory of Japan
Jordy Davelaar
Radboud University
Columbia University
Flatiron Institute
Mariafelicia De Laurentis
Goethe University Frankfurt
National Institute for Nuclear Physics
University of Naples Federico II
Roger Deane
University of Witwatersrand
University of Pretoria
Rhodes University
Jessica Dempsey
East Asian Observatory
Netherlands Institute for Radio Astronomy (ASTRON)
James Clerk Maxwell Telescope
Gregory Desvignes
Paris Descartes University
Max Planck Society
Jason Dexter
University of Colorado at Boulder
Vedant Dhruv
University of Illinois
Sheperd S. Doeleman
Harvard-Smithsonian Center for Astrophysics
Harvard University
Sean Dougal
University of Arizona
Sergio A. Dzib
Institut de Radioastronomie Millimétrique (IRAM)
Max Planck Society
Ralph P. Eatough
Chinese Academy of Sciences
Max Planck Society
Razieh Emami
Harvard-Smithsonian Center for Astrophysics
Heino Falcke
Radboud University
Joseph Farah
University of California at Santa Barbara
Las Cumbres Observatory Global Telescope Network
Vincent L. Fish
Massachusetts Institute of Technology (MIT)
Ed Fomalont
National Radio Astronomy Observatory
H. Alyson Ford
University of Arizona
Raquel Fraga-Encinas
Radboud University
William T. Freeman
Massachusetts Institute of Technology (MIT)
Google Inc.
Per Friberg
James Clerk Maxwell Telescope
East Asian Observatory
Christian M. Fromm
Max Planck Society
University of Würzburg
Goethe University Frankfurt
Antonio Fuentes
Spanish National Research Council (CSIC)
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 Waterloo
Perimeter Institute for Theoretical Physics
Ciriaco Goddi
Istituto nazionale di astrofisica (INAF)
University of Cagliari
Roman Gold
University of Southern Denmark
Goethe University Frankfurt
Gomez-Ruiz
National Council for Science and Technology Mexico
National Institute of Astrophysics, Optics and Electronics
Jose L. Gomez
Spanish National Research Council (CSIC)
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)
Daryl Haggard
McGill University
Kari Haworth
Harvard-Smithsonian Center for Astrophysics
Michael H. Hecht
Massachusetts Institute of Technology (MIT)
Ronald Hesper
University of Groningen
Dirk Heumann
University of Arizona
Luis C. Ho
Beijing University of Technology
Paul Ho
James Clerk Maxwell Telescope
Academia Sinica
Mareki Honma
University of Tokyo
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
The Graduate University for Advanced Studies (SOKENDAI)
University of Tokyo
C. M. Violette Impellizzeri
Leiden University
National Radio Astronomy Observatory
Makoto Inoue
Academia Sinica
Sara Issaoun
NASA Hubble Fellowship Program
Harvard-Smithsonian Center for Astrophysics
David J. James
ASTRAVEO
Buell T. Jannuzi
University of Arizona
Michael Janssen
Max Planck Society
Britton Jeter
Academia Sinica
Wu Jiang
Chinese Academy of Sciences
Alejandra Jimenez-Rosales
Radboud University
Michael D. Johnson
Harvard-Smithsonian Center for Astrophysics
Harvard University
Svetlana Jorstad
Boston University
Joshi
University of Illinois
Taehyun Jung
Korea Astronomy and Space Science Institute
University of Science and Technology (UST)
Mansour Karami
University of Waterloo
Perimeter Institute for Theoretical Physics
Ramesh Karuppusamy
Max Planck Society
Tomohisa Kawashima
University of Tokyo
Garrett K. Keating
Harvard-Smithsonian Center for Astrophysics
Mark Kettenis
Joint Institute for VLBI in Europe (JIVE)
Dong-Jin Kim
Max Planck Society
Jae-Young Kim
Max Planck Society
Korea Astronomy and Space Science Institute
Kyungpook National University
Jongsoo Kim
Korea Astronomy and Space Science Institute
Junhan Kim
California Institute of Technology (Caltech)
University of Arizona
Motoki Kino
National Astronomical Observatory of Japan
Kogakuin University of Technology and Engineering
Jun Yi Koay
Academia Sinica
Prashant Kocherlakota
Goethe University Frankfurt
Yutaro Kofuji
University of Tokyo
National Astronomical Observatory of Japan
Patrick M. Koch
Academia Sinica
Shoko Koyama
Niigata University
Academia Sinica
Carsten Kramer
Institut de Radioastronomie Millimétrique (IRAM)
Michael Kramer
Max Planck Society
Thomas P. Krichbaum
Max Planck Society
Cheng-Yu Kuo
Academia Sinica
National Sun Yat-Sen University
Noemi La Bella
Radboud University
Tod R. Lauer
National Optical Astronomy Observatory
Daeyoung Lee
University of Illinois
Sang-Sung Lee
Korea Astronomy and Space Science Institute
Po Kin Leung
Chinese University of Hong Kong
Aviad Levis
California Institute of Technology (Caltech)
Zhiyuan Li
Nanjing University
Rocco Lico
Istituto nazionale di astrofisica (INAF)
Spanish National Research Council (CSIC)
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
Italian ALMA Regional Centre
Istituto nazionale di astrofisica (INAF)
Wen-Ping Lo
Academia Sinica
National Taiwan University
Andrei P. Lobanov
Max Planck Society
Laurent Loinard
Universidad Nacional Autónoma de México
Colin J. Lonsdale
Massachusetts Institute of Technology (MIT)
Ru-Sen Lu
Max Planck Society
Chinese Academy of Sciences
Jirong Mao
Chinese Academy of Sciences
Nicola Marchili
Istituto nazionale di astrofisica (INAF)
Italian ALMA Regional Centre
Max Planck Society
Sera Markoff
University of Amsterdam
Daniel P. Marrone
University of Arizona
Alan P. Marscher
Boston University
Ivan Marti-Vidal
Universitat de Valencia
Satoki Matsushita
Academia Sinica
Lynn D. Matthews
Massachusetts Institute of Technology (MIT)
Lia Medeiros
University of Arizona
Institute for Advanced Study
Karl M. Menten
Max Planck Society
Daniel Michalik
University of Chicago
European Space Research and Technology Centre (ESA ESTEC)
Izumi Mizuno
East Asian Observatory
James Clerk Maxwell Telescope
Yosuke Mizuno
Goethe University Frankfurt
Shanghai Jiao Tong University
James M. Moran
Harvard-Smithsonian Center for Astrophysics
Harvard University
Kotaro Moriyama
National Astronomical Observatory of Japan
Massachusetts Institute of Technology (MIT)
Goethe University Frankfurt
Monika Moscibrodzka
Radboud University
Cornelia Muller
Radboud University
Max Planck Society
Alejandro Mus
Universitat de Valencia
Gibwa Musoke
University of Amsterdam
Radboud University
Ioannis Myserlis
Institut de Radioastronomie Millimétrique (IRAM)
Andrew Nadolski
University of Illinois
Hiroshi Nagai
National Astronomical Observatory of Japan
The Graduate University for Advanced Studies (SOKENDAI)
Neil M. Nagar
University of Concepcion
Masanori Nakamura
National Institute of Technology, Hachinohe College
Academia Sinica
Ramesh Narayan
Harvard University
Harvard-Smithsonian Center for Astrophysics
Gopal Narayanan
University of Massachusetts
Iniyan Natarajan
South African Radio Astronomy Observatory (SARAO)
University of Witwatersrand
Antonios Nathanail
Goethe University Frankfurt
National and Kapodistrian University of Athens
Santiago Navarro Fuentes
Institut de Radioastronomie Millimétrique (IRAM)
Joey Neilsen
Villanova University
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Institut de Radioastronomie Millimétrique (IRAM)
Chunchong Ni
Perimeter Institute for Theoretical Physics
University of Waterloo
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Max Planck Society
Michael A. Nowak
Washington University in St. Louis
Junghwan Oh
Sejong University
Hiroki Okino
University of Tokyo
National Astronomical Observatory of Japan
Hector Olivares
Radboud University
Gisela N. Ortiz-Leon
Universidad Nacional Autónoma de México
Max Planck Society
Tomoaki Oyama
National Astronomical Observatory of Japan
Daniel C. M. Palumbo
Harvard-Smithsonian Center for Astrophysics
Harvard University
Georgios Filippos Paraschos
Max Planck Society
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Academia Sinica
Harriet Parsons
James Clerk Maxwell Telescope
East Asian Observatory
Nimesh Patel
Harvard-Smithsonian Center for Astrophysics
Ue-Li Pen
University of Toronto
Canadian Institute for Advanced Research
Academia Sinica
Perimeter Institute for Theoretical Physics
Dominic W. Pesce
Harvard University
Harvard-Smithsonian Center for Astrophysics
Vincent Pietu
Institut de Radioastronomie Millimétrique (IRAM)
Richard Plambeck
University of California at Berkeley
Aleksandar PopStefanija
University of Massachusetts
Oliver Porth
Goethe University Frankfurt
University of Amsterdam
Felix M. Potzl
Max Planck Society
University College Cork
Ben Prather
University of Illinois
Jorge A. Preciado-Lopez
Perimeter Institute for Theoretical Physics
Hung-Yi Pu
National Taiwan Normal University
Academia Sinica
Venkatessh Ramakrishnan
Aalto University
University of Turku
University of Concepcion
Ramprasad Rao
Harvard-Smithsonian Center for Astrophysics
Mark G. Rawlings
Gemini Observatory North
East Asian Observatory
James Clerk Maxwell Telescope
Alexander W. Raymond
Harvard-Smithsonian Center for Astrophysics
Harvard University
Luciano Rezzolla
Goethe University Frankfurt
Frankfurt Institute for Advanced Studies
Trinity College Dublin
Angelo Ricarte
Harvard University
Harvard-Smithsonian Center for Astrophysics
Bart Ripperda
Flatiron Institute
Princeton University
Freek Roelofs
Harvard University
Radboud University
Harvard-Smithsonian Center for Astrophysics
Alan Rogers
Massachusetts Institute of Technology (MIT)
Eduardo Ros
Max Planck Society
Cristina Romero-Canizales
Academia Sinica
Arash Roshanineshat
University of Arizona
Helge Rottmann
Max Planck Society
Alan L. Roy
Max Planck Society
Ignacio Ruiz
Institut de Radioastronomie Millimétrique (IRAM)
Chet Ruszczyk
Massachusetts Institute of Technology (MIT)
Kazi L. J. Rygl
Italian ALMA Regional Centre
Istituto nazionale di astrofisica (INAF)
Salvador Sanchez
Institut de Radioastronomie Millimétrique (IRAM)
David Sanchez-Arguelles
National Institute of Astrophysics, Optics and Electronics
National Council for Science and Technology Mexico
Miguel Sanchez-Portal
Institut de Radioastronomie Millimétrique (IRAM)
Mahito Sasada
National Astronomical Observatory of Japan
Tokyo Institute of Technology
Hiroshima University
Kaushik Satapathy
University of Arizona
Tuomas Savolainen
Aalto University
Max Planck Society
F. Peter Schloerb
University of Massachusetts
Jonathan Schonfeld
Harvard-Smithsonian Center for Astrophysics
Karl-Friedrich Schuster
Institut de Radioastronomie Millimétrique (IRAM)
Lijing Shao
Beijing University of Technology
Max Planck Society
Zhiqiang Shen
Chinese Academy of Sciences
Des Small
Joint Institute for VLBI in Europe (JIVE)
Bong Won Sohn
University of Science and Technology (UST)
Korea Astronomy and Space Science Institute
Yonsei University
East Asian Observatory
James Clerk Maxwell Telescope
Jason SooHoo
Massachusetts Institute of Technology (MIT)
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University of Massachusetts
He Sun
California Institute of Technology (Caltech)
Fumie Tazaki
National Astronomical Observatory of Japan
Alexandra J. Tetarenko
Texas Tech University at Lubbock
NASA Hubble Fellowship Program
Paul Tiede
Harvard-Smithsonian Center for Astrophysics
Harvard University
Remo P. J. Tilanus
University of Arizona
Leiden University
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Massachusetts Institute of Technology (MIT)
Pablo Torne
Institut de Radioastronomie Millimétrique (IRAM)
Max Planck Society
Efthalia Traianou
Max Planck Society
Spanish National Research Council (CSIC)
Tyler Trent
University of Arizona
Sascha Trippe
Seoul National University
Matthew Turk
University of Illinois
Ilse van Bemmel
Joint Institute for VLBI in Europe (JIVE)
Huib Jan van Langevelde
University of New Mexico
Joint Institute for VLBI in Europe (JIVE)
Leiden University
Daniel R. van Rossum
Radboud University
Jesse Vos
Radboud University
Jan Wagner
Max Planck Society
Derek Ward-Thompson
University of Central Lancashire
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Brandeis University
Jonathan Weintroub
Harvard University
Harvard-Smithsonian Center for Astrophysics
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Max Planck Society
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Max Planck Society
Maciek Wielgus
Max Planck Society
Kaj Wiik
University of Turku
Gunther Witzel
Max Planck Society
Michael F. Wondrak
Radboud University
George N. Wong
Princeton University
Institute for Advanced Study
Qingwen Wu
Huazhong University of Science and Technology
Paul Yamaguchi
Harvard-Smithsonian Center for Astrophysics
Doosoo Yoon
University of Amsterdam
Andre Young
Radboud University
Ken Young
Harvard-Smithsonian Center for Astrophysics
Ziri Younsi
Goethe University Frankfurt
University College London (UCL)
Feng Yuan
Chinese Academy of Sciences
Ye-Fei Yuan
James Clerk Maxwell Telescope
East Asian Observatory
University of Science and Technology of China
J. Anton Zensus
Max Planck Society
Shuo Zhang
Bard College
Guang-Yao Zhao
Spanish National Research Council (CSIC)
Shan-Shan Zhao
Chinese Academy of Sciences
Dominic O. Chang
Harvard University
Harvard-Smithsonian Center for Astrophysics
Astrophysical Journal Letters
2041-8205 (ISSN) 2041-8213 (eISSN)
Vol. 930 2 L15Subject Categories
Astronomy, Astrophysics and Cosmology
Geophysics
Probability Theory and Statistics
DOI
10.3847/2041-8213/ac6736