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
Massachusetts Institute of Technology (MIT)
Harvard University
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
James Clerk Maxwell Telescope
East Asian Observatory
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-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 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
National Aeronautics and Space Administration (NASA)
Princeton University
Chi-kwan Chan
University of Arizona
Koushik Chatterjee
Harvard University
Harvard-Smithsonian Center for Astrophysics
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
University of Illinois
Harvard-Smithsonian Center for Astrophysics
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
National Astronomical Observatory of Japan
The Graduate University for Advanced Studies (SOKENDAI)
Jordy Davelaar
Flatiron Institute
Columbia University
Radboud University
Mariafelicia De Laurentis
University of Naples Federico II
Goethe University Frankfurt
National Institute for Nuclear Physics
Roger Deane
Rhodes University
University of Pretoria
University of Witwatersrand
Jessica Dempsey
James Clerk Maxwell Telescope
East Asian Observatory
Netherlands Institute for Radio Astronomy (ASTRON)
Gregory Desvignes
Max Planck Society
Paris Descartes University
Jason Dexter
University of Colorado at Boulder
Vedant Dhruv
University of Illinois
Sheperd S. Doeleman
Harvard University
Harvard-Smithsonian Center for Astrophysics
Sean Dougal
University of Arizona
Sergio A. Dzib
Institut de Radioastronomie Millimétrique (IRAM)
Max Planck Society
Ralph P. Eatough
Max Planck Society
Chinese Academy of Sciences
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
Google Inc.
Massachusetts Institute of Technology (MIT)
Per Friberg
James Clerk Maxwell Telescope
East Asian Observatory
Christian M. Fromm
Goethe University Frankfurt
University of Würzburg
Max Planck Society
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
University of Cagliari
Istituto nazionale di astrofisica (INAF)
Roman Gold
University of Southern Denmark
Goethe University Frankfurt
Gomez-Ruiz
National Institute of Astrophysics, Optics and Electronics
National Council for Science and Technology Mexico
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
The Graduate University for Advanced Studies (SOKENDAI)
National Astronomical Observatory of Japan
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
National Radio Astronomy Observatory
Leiden University
Makoto Inoue
Academia Sinica
Sara Issaoun
National Aeronautics and Space Administration (NASA)
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
Perimeter Institute for Theoretical Physics
University of Waterloo
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
Kyungpook National University
Max Planck Society
Korea Astronomy and Space Science Institute
Jongsoo Kim
Korea Astronomy and Space Science Institute
Junhan Kim
University of Arizona
California Institute of Technology (Caltech)
Motoki Kino
Kogakuin University of Technology and Engineering
National Astronomical Observatory of Japan
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
National Sun Yat-Sen University
Academia Sinica
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
Spanish National Research Council (CSIC)
Istituto nazionale di astrofisica (INAF)
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 nazionale di astrofisica (INAF)
Italian ALMA Regional Centre
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
Chinese Academy of Sciences
Max Planck Society
Jirong Mao
Chinese Academy of Sciences
Nicola Marchili
Istituto nazionale di astrofisica (INAF)
Max Planck Society
Italian ALMA Regional Centre
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
European Space Research and Technology Centre (ESA ESTEC)
University of Chicago
Izumi Mizuno
James Clerk Maxwell Telescope
East Asian Observatory
Yosuke Mizuno
Shanghai Jiao Tong University
Goethe University Frankfurt
James M. Moran
Harvard-Smithsonian Center for Astrophysics
Harvard University
Kotaro Moriyama
Massachusetts Institute of Technology (MIT)
National Astronomical Observatory of Japan
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-Smithsonian Center for Astrophysics
Harvard University
Gopal Narayanan
University of Massachusetts
Iniyan Natarajan
University of Witwatersrand
South African Radio Astronomy Observatory (SARAO)
Antonios Nathanail
National and Kapodistrian University of Athens
Goethe University Frankfurt
Santiago Navarro Fuentes
Institut de Radioastronomie Millimétrique (IRAM)
Joseph Neilsen
Villanova University
Roberto Neri
Institut de Radioastronomie Millimétrique (IRAM)
Chunchong Ni
University of Waterloo
Perimeter Institute for Theoretical Physics
Aristeidis Noutsos
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
Max Planck Society
Universidad Nacional Autónoma de México
Tomoaki Oyama
National Astronomical Observatory of Japan
Daniel C. M. Palumbo
Harvard-Smithsonian Center for Astrophysics
Harvard University
Georgios Filippos Paraschos
Max Planck Society
Jongho Park
Academia Sinica
Harriet Parsons
East Asian Observatory
James Clerk Maxwell Telescope
Nimesh Patel
Harvard-Smithsonian Center for Astrophysics
Ue-Li Pen
Academia Sinica
University of Toronto
Canadian Institute for Advanced Research
Perimeter Institute for Theoretical Physics
Dominic W. Pesce
Harvard-Smithsonian Center for Astrophysics
Harvard University
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
University of Concepcion
Aalto University
University of Turku
Ramprasad Rao
Harvard-Smithsonian Center for Astrophysics
Mark G. Rawlings
Gemini Observatory North
James Clerk Maxwell Telescope
East Asian Observatory
Alexander W. Raymond
Harvard-Smithsonian Center for Astrophysics
Harvard University
Luciano Rezzolla
Frankfurt Institute for Advanced Studies
Goethe University Frankfurt
Trinity College Dublin
Angelo Ricarte
Harvard-Smithsonian Center for Astrophysics
Harvard University
Bart Ripperda
Flatiron Institute
Princeton University
Freek Roelofs
Harvard-Smithsonian Center for Astrophysics
Harvard University
Radboud University
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
Istituto nazionale di astrofisica (INAF)
Italian ALMA Regional Centre
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
Hiroshima University
Tokyo Institute of Technology
National Astronomical Observatory of Japan
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)
Yonsei University
James Clerk Maxwell Telescope
East Asian Observatory
Korea Astronomy and Space Science Institute
Jason SooHoo
Massachusetts Institute of Technology (MIT)
Kamal Souccar
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
National Aeronautics and Space Administration (NASA)
Paul Tiede
Harvard-Smithsonian Center for Astrophysics
Harvard University
Remo P. J. Tilanus
University of Arizona
Netherlands Organisation for Scientific Research (NWO)
Leiden University
Radboud University
Michael Titus
Massachusetts Institute of Technology (MIT)
Pablo Torne
Max Planck Society
Institut de Radioastronomie Millimétrique (IRAM)
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
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
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
University College London (UCL)
Goethe University Frankfurt
Feng Yuan
Chinese Academy of Sciences
Ye-Fei Yuan
East Asian Observatory
University of Science and Technology of China
James Clerk Maxwell Telescope
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 (SSIF 2011)
Astronomy, Astrophysics and Cosmology
Geophysics
Probability Theory and Statistics
DOI
10.3847/2041-8213/ac6736