Characterizing and Mitigating Intraday Variability: Reconstructing Source Structure in Accreting Black Holes with mm-VLBI
Journal article, 2022
The extraordinary physical resolution afforded by the Event Horizon Telescope has opened a window onto the astrophysical phenomena unfolding on horizon scales in two known black holes, M87* and Sgr A*. However, with this leap in resolution has come a new set of practical complications. Sgr A* exhibits intraday variability that violates the assumptions underlying Earth aperture synthesis, limiting traditional image reconstruction methods to short timescales and data sets with very sparse (u, v) coverage. We present a new set of tools to detect and mitigate this variability. We develop a data-driven, model-agnostic procedure to detect and characterize the spatial structure of intraday variability. This method is calibrated against a large set of mock data sets, producing an empirical estimator of the spatial power spectrum of the brightness fluctuations. We present a novel Bayesian noise modeling algorithm that simultaneously reconstructs an average image and statistical measure of the fluctuations about it using a parameterized form for the excess variance in the complex visibilities not otherwise explained by the statistical errors. These methods are validated using a variety of simulated data, including general relativistic magnetohydrodynamic simulations appropriate for Sgr A* and M87*. We find that the reconstructed source structure and variability are robust to changes in the underlying image model. We apply these methods to the 2017 EHT observations of M87*, finding evidence for variability across the EHT observing campaign. The variability mitigation strategies presented are widely applicable to very long baseline interferometry observations of variable sources generally, for which they provide a data-informed averaging procedure and natural characterization of inter-epoch image consistency.
Author
Avery E. Broderick
Perimeter Institute for Theoretical Physics
University of Waterloo
Roman Gold
University of Southern Denmark
Goethe University Frankfurt
Boris Georgiev
University of Waterloo
Perimeter Institute for Theoretical Physics
Dominic W. Pesce
Harvard University
Harvard-Smithsonian Center for Astrophysics
Paul Tiede
Harvard University
Harvard-Smithsonian Center for Astrophysics
Chunchong Ni
Perimeter Institute for Theoretical Physics
University of Waterloo
Kotaro Moriyama
Massachusetts Institute of Technology (MIT)
Goethe University Frankfurt
National Astronomical Observatory of Japan
Kazunori Akiyama
Harvard University
National Astronomical Observatory of Japan
Massachusetts Institute of Technology (MIT)
Antxon Alberdi
Spanish National Research Council (CSIC)
Walter Alef
Max Planck Society
Juan Carlos Algaba
University of Malaya
Richard Anantua
University of Texas at San Antonio
Harvard University
Harvard-Smithsonian Center for Astrophysics
Keiichi Asada
Academia Sinica
Rebecca Azulay
Max Planck Society
Universitat de Valencia
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
University of Chicago
Fermi National Accelerator Laboratory
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
Dominique Broguiere
Institut de Radioastronomie Millimétrique (IRAM)
Thomas Bronzwaer
Radboud University
Sandra Bustamante
University of Massachusetts
Do-Young Byun
University of Science and Technology (UST)
Korea Astronomy and Space Science Institute
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 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
National Astronomical Observatory of Japan
Shanghai Jiao Tong University
The Graduate University for Advanced Studies (SOKENDAI)
Jordy Davelaar
Flatiron Institute
Radboud University
Columbia University
Mariafelicia De Laurentis
National Institute for Nuclear Physics
University of Naples Federico II
Goethe University Frankfurt
Roger Deane
University of Pretoria
University of Witwatersrand
Rhodes University
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
Max Planck Society
Institut de Radioastronomie Millimétrique (IRAM)
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
East Asian Observatory
James Clerk Maxwell Telescope
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)
Ciriaco Goddi
University of Cagliari
INAF Osservatorio Astronomico di Cagliari
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
The Graduate University for Advanced Studies (SOKENDAI)
National Astronomical Observatory of Japan
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
Academia Sinica
James Clerk Maxwell Telescope
Mareki Honma
National Astronomical Observatory of Japan
University of Tokyo
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
The Graduate University for Advanced Studies (SOKENDAI)
University of Tokyo
National Astronomical Observatory of Japan
The Institute of Statistical Mathematics
C. M. Violette Impellizzeri
National Radio Astronomy Observatory
Leiden University
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 University
Harvard-Smithsonian Center for Astrophysics
Svetlana Jorstad
Saint Petersburg State University - Spsu
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
Korea Astronomy and Space Science Institute
Kyungpook National University
Max Planck Society
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
Academia Sinica
Niigata University
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
Russian Academy of Sciences
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 Autonoma de Mexico
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)
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 University
Harvard-Smithsonian Center for Astrophysics
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
South African Radio Astronomy Observatory (SARAO)
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National and Kapodistrian University of Athens
Goethe University Frankfurt
Santiago Navarro Fuentes
Institut de Radioastronomie Millimétrique (IRAM)
Joey Neilsen
Villanova University
Roberto Neri
Institut de Radioastronomie Millimétrique (IRAM)
Aristeidis Noutsos
Max Planck Society
Michael A. Nowak
Washington University in St. Louis
Junghwan Oh
Sejong University
Hiroki Okino
National Astronomical Observatory of Japan
University of Tokyo
Hector Olivares
Radboud University
Gisela N. Ortiz-Leon
Universidad Nacional Autonoma de Mexico
Max Planck Society
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National Astronomical Observatory of Japan
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Harvard University
Harvard-Smithsonian Center for Astrophysics
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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
Canadian Institute for Advanced Research
University of Toronto
Academia Sinica
Perimeter Institute for Theoretical Physics
Vincent Pietu
Institut de Radioastronomie Millimétrique (IRAM)
Richard Plambeck
University of California at Berkeley
Aleksandar PopStefanija
University of Massachusetts
Oliver Porth
University of Amsterdam
Goethe University Frankfurt
Felix M. Potzl
University College Cork
Max Planck Society
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 Turku
Aalto University
University of Concepcion
Ramprasad Rao
Harvard-Smithsonian Center for Astrophysics
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East Asian Observatory
Gemini Observatory North
James Clerk Maxwell Telescope
Alexander W. Raymond
Harvard University
Harvard-Smithsonian Center for Astrophysics
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Goethe University Frankfurt
Frankfurt Institute for Advanced Studies
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Harvard-Smithsonian Center for Astrophysics
Harvard University
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Princeton University
Flatiron Institute
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Harvard University
Harvard-Smithsonian Center for Astrophysics
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Massachusetts Institute of Technology (MIT)
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Max Planck Society
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Academia Sinica
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University of Arizona
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Max Planck Society
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Max Planck Society
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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 Council for Science and Technology Mexico
National Institute of Astrophysics, Optics and Electronics
Miguel Sanchez-Portal
Institut de Radioastronomie Millimétrique (IRAM)
Mahito Sasada
National Astronomical Observatory of Japan
Hiroshima University
Tokyo Institute of Technology
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University of Arizona
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Aalto University
Max Planck Society
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University of Massachusetts
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Harvard-Smithsonian Center for Astrophysics
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Institut de Radioastronomie Millimétrique (IRAM)
Lijing Shao
Max Planck Society
Beijing University of Technology
Zhiqiang Shen
Chinese Academy of Sciences
Des Small
Joint Institute for VLBI in Europe (JIVE)
Bong Won Sohn
James Clerk Maxwell Telescope
Yonsei University
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East Asian Observatory
University of Science and Technology (UST)
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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
Remo P. J. Tilanus
Radboud University
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Massachusetts Institute of Technology (MIT)
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Institut de Radioastronomie Millimétrique (IRAM)
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Spanish National Research Council (CSIC)
Max Planck Society
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
Leiden University
University of New Mexico
Joint Institute for VLBI in Europe (JIVE)
Daniel R. van Rossum
Radboud University
Jesse Vos
Radboud University
Jan Wagner
Max Planck Society
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University of Central Lancashire
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Brandeis University
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Harvard-Smithsonian Center for Astrophysics
Harvard University
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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
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Radboud University
George N. Wong
Institute for Advanced Study
Princeton University
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
University of Science and Technology of China
James Clerk Maxwell Telescope
East Asian Observatory
J. Anton Zensus
Max Planck Society
Guang-Yao Zhao
Spanish National Research Council (CSIC)
Shuo Zhang
Bard College
Shan-Shan Zhao
Chinese Academy of Sciences
Astrophysical Journal Letters
2041-8205 (ISSN) 2041-8213 (eISSN)
Vol. 930 2 L21Subject Categories
Probability Theory and Statistics
Computer Vision and Robotics (Autonomous Systems)
Medical Image Processing
DOI
10.3847/2041-8213/ac6584