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Cited by 38Astrophysical Phenomena and ObservationsRadio Astronomy Observations and TechnologyPulsars and Gravitational Waves Research

Characterizing and Mitigating Intraday Variability: Reconstructing Source Structure in Accreting Black Holes with mm-VLBI

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Broderick, Avery E., Gold, Roman, Georgiev, Boris, Pesce, Dominic W., Tiede, Paul, Ni, Chunchong, Moriyama, Kotaro, Akiyama, Kazunori +259 more·2022·The Astrophysical Journal Letters
DOI 10.3847/2041-8213/ac6584
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Abstract

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.

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  • Broderick et al. (2022) derive the debiasing function using the same 90 GRMHD simulations used in this paper for θg calibration, and the resulting debiasing factor is close to unity everywhere except between ∼6 and 7.5 Gλ.

    “In practice, Broderick et al. ( 2022 ) derive the debiasing function using the same 90 GRMHD simulations we use in this paper for θ g calibration ( see Section 4.4 and Appendix D ) , and the resulting debiasing factor is close to unity everywhere except between ∼ 6 and 7.5 G λ ( see Figure 5 in Broderick et al. 2022 ) .”

    From First Sagittarius A* Event Horizon Telescope Results. IV. Variability, Morphology, and Black Hole Mass (2022) · cites this paper as Broderick et al. 2022

    Section 4.5 says the debiasing function was estimated from the 90 GRMHD simulations used for the Paper IV calibration. Its Figure 6 caption identifies 6–7.5 Gλ as the region with significant variance underestimates, but the copy does not establish that the factor is close to unity everywhere else: estimates are inaccurate below 2 Gλ and there are no data above 9 Gλ. The citing sentence also points to Figure 5, whereas the paper identifies Figure 6 as the debiasing-function figure. (LLM, conf=0.85)

    Experimental — accuracy not yet measured

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Research works printed but not linked: 1

  1. Thompson, A. R., Moran, J. M., & Swenson, G. W., Jr. 2017, Interferometry and Synthesis in Radio Astronomy (Cham: Springer)

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Authors
Broderick, A. E., Gold, R., Georgiev, B., Pesce, D. W., Tiede, P., Ni, C., Moriyama, K., Akiyama, K., Alberdi, A., Alef, W., Algaba, J. C., Anantua, R., Asada, K., Azulay, R., Bach, U., Baczko, A.-K., Ball, D., Baloković, M., Barrett, J., Bauböck, M., Benson, B. A., Bintley, D., Blackburn, L., Blundell, R., Bouman, K. L., Bower, G. C., Boyce, H., Bremer, M., Brinkerink, C. D., Brissenden, R., Britzen, S., Broguiere, D., Bronzwaer, T., Bustamante, S., Byun, D.-Y., Carlstrom, J. E., Ceccobello, C., Chael, A., Chan, C.-K., Chatterjee, K., Chatterjee, S., Chen, M.-T., Chen 陈, Y. 永., Cheng, X., Cho, I., Christian, P., Conroy, N. S., Conway, J. E., Cordes, J. M., Crawford, T. M., Crew, G. B., Cruz-Osorio, A., Cui 崔, Y. 玉., Davelaar, J., De Laurentis, M., Deane, R., Dempsey, J., Desvignes, G., Dexter, J., Dhruv, V., Doeleman, S. S., Dougal, S., Dzib, S. A., Eatough, R. P., Emami, R., Falcke, H., Farah, J., Fish, V. L., Fomalont, E., Ford, H. A., Fraga-Encinas, R., Freeman, W. T., Friberg, P., Fromm, C. M., Fuentes, A., Galison, P., Gammie, C. F., García, R., Gentaz, O., Goddi, C., Gómez-Ruiz, A. I., Gómez, J. L., Gu 顾, M. 敏., Gurwell, M., Hada, K., Haggard, D., Haworth, K., Hecht, M. H., Hesper, R., Heumann, D., Ho 何, L. C. 子., Ho, P., Honma, M., Huang 黄, C.-W. L. 磊., Huang, L., Hughes, D. H., Ikeda, S., Impellizzeri, C. M. V., Inoue, M., Issaoun, S., James, D. J., Jannuzi, B. T., Janssen, M., Jeter, B., Jiang 江, W. 悟., Jiménez-Rosales, A., Johnson, M. D., Jorstad, S., Joshi, A. V., Jung, T., Karami, M., Karuppusamy, R., Kawashima, T., Keating, G. K., Kettenis, M., Kim, D.-J., Kim, J.-Y., Kim, J., Kim, J., Kino, M., Koay, J. Y., Kocherlakota, P., Kofuji, Y., Koch, P. M., Koyama, S., Kramer, C., Kramer, M., Krichbaum, T. P., Kuo, C.-Y., Bella, N. L., Lauer, T. R., Lee, D., Lee, S.-S., Leung, P. K., Levis, A., Li 李, Z. 志., Lico, R., Lindahl, G., Lindqvist, M., Lisakov, M., Liu 刘, J. 俊., Liu, K., Liuzzo, E., Lo, W.-P., Lobanov, A. P., Loinard, L., Lonsdale, C. J., Lu 路, R.-S. 如., Mao 毛, J. 基., Marchili, N., Markoff, S., Marrone, D. P., Marscher, A. P., Martí-Vidal, I., Matsushita, S., Matthews, L. D., Menten, K. M., Michalik, D., Mizuno, I., Mizuno, Y., Moran, J. M., Moscibrodzka, M., Müller, C., Mus, A., Musoke, G., Myserlis, I., Nadolski, A., Nagai, H., Nagar, N. M., Nakamura, M., Narayan, R., Narayanan, G., Natarajan, I., Nathanail, A., Fuentes, S. N., Neilsen, J., Neri, R., Noutsos, A., Nowak, M. A., Oh, J., Okino, H., Olivares, H., Ortiz-León, G. N., Oyama, T., Palumbo, D. C. M., Paraschos, G. F., Park, J., Parsons, H., Patel, N., Pen, U.-L., Piétu, V., Plambeck, R., PopStefanija, A., Porth, O., Pötzl, F. M., Prather, B., Preciado-López, J. A., Pu, H.-Y., Ramakrishnan, V., Rao, R., Rawlings, M. G., Raymond, A. W., Rezzolla, L., Ricarte, A., Ripperda, B., Roelofs, F., Rogers, A., Ros, E., Romero-Cañizales, C., Roshanineshat, A., Rottmann, H., Roy, A. L., Ruiz, I., Ruszczyk, C., Rygl, K. L. J., Sánchez, S., Sánchez-Argüelles, D., Sánchez-Portal, M., Sasada, M., Satapathy, K., Savolainen, T., Schloerb, F. P., Schonfeld, J., Schuster, K.-F., Shao, L., Shen 沈, Z. 志., Small, D., Sohn, B. W., SooHoo, J., Souccar, K., Sun 孙, H. 赫., Tazaki, F., Tetarenko, A. J., Tilanus, R. P. J., Titus, M., Torne, P., Traianou, E., Trent, T., Trippe, S., Turk, M., van Bemmel, I., van Langevelde, H. J., van Rossum, D. R., Vos, J., Wagner, J., Ward-Thompson, D., Wardle, J., Weintroub, J., Wex, N., Wharton, R., Wielgus, M., Wiik, K., Witzel, G., Wondrak, M. F., Wong, G. N., Wu 吴, Q. 庆., Yamaguchi, P., Yoon, D., Young, A., Young, K., Younsi, Z., Yuan 袁, F. 峰., Yuan 袁, Y.-F. 业., Zensus, J. A., Zhao, G.-Y., Zhang, S., & Zhao 赵, S.-S. 杉.
Affiliations
  • University of Waterloo (CA)
  • Goethe University Frankfurt (DE)
  • Harvard University (US)
  • Perimeter Institute (CA)
  • Max Planck Institute for Radio Astronomy (DE)
  • Institute of Astronomy and Astrophysics, Academia Sinica (TW)
  • Universitat de València (ES)
  • University of Arizona (US)
  • Massachusetts Institute of Technology (US)
  • Fermi National Accelerator Laboratory (US)
  • East Asian Observatory (US)
  • Center for Astrophysics Harvard & Smithsonian (US)
  • California Institute of Technology (US)
  • University of Hawaiʻi at Mānoa (US)
  • Radboud University Nijmegen (NL)
  • University of Southern Denmark (DK)
  • Fairfield University (US)
  • University of Illinois Urbana-Champaign (US)
  • Las Cumbres Observatory Global Telescope Network (US)
  • Google (United States) (US)
  • Kavli Institute for the Physics and Mathematics of the Universe (JP)
  • Leiden University (NL)
  • Boston University (US)
  • Institute for Cosmic Ray Research (JP)
  • Kogakuin University (JP)
  • National Astronomical Observatory of Japan (JP)
  • Chinese University of Hong Kong (HK)
  • Istituto di Radioastronomia di Bologna (IT)
  • P.N. Lebedev Physical Institute of the Russian Academy of Sciences (RU)
  • Instituto de Radioastronomía Milimétrica (ES)
  • University of Concepción (CL)
  • University of the Witwatersrand (ZA)
  • Instituto de Astrofísica de Andalucía (ES)
  • Washington University in St. Louis (US)
  • Sejong University (KR)
  • Canadian Institute for Advanced Research (CA)
  • Hiroshima University (JP)
  • Yonsei University (KR)
  • Texas Tech University (US)
  • Seoul National University (KR)
  • University of Lancashire (GB)
  • The University of Texas at San Antonio (US)
  • University of Turku (FI)
  • Princeton University (US)
  • Bard College (US)
Corresponding author
Broderick, Avery E.
ORCID
Venue
The Astrophysical Journal Letters
Publisher
American Astronomical Society
Published
2022-05-01
Volume
930
Issue
2
Pages
L21
ISSN
  • 2041-8205 (ISSN-L)
  • 2041-8213
DOI
10.3847/2041-8213/ac6584
OpenAlex
W4280560568
Cited by
38
References
52
Citations by year
2026: 5 · 2025: 5 · 2024: 8 · 2023: 9 · 2022: 11
FWCI
3.30
Type
journal article
Language
en
Open access
Licence
Locations
  • The Astrophysical Journal Letters (publishedVersion, cc-by)
  • OpenBU (Boston University) (publishedVersion, cc-by)
  • University of Groningen research database (University of Groningen / Centre for Information Technology) (publishedVersion, cc-by)
  • CLOK (University of Central Lancashire) (acceptedVersion)
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  • OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information) (submittedVersion, cc-by)
  • Chalmers Research (Chalmers University of Technology) (submittedVersion, cc-by)
  • UTUPub (University of Turku) (submittedVersion, cc-by)
  • CaltechAUTHORS (California Institute of Technology) (submittedVersion, cc-by)
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  • Data Archiving and Networked Services (DANS) (submittedVersion, cc-by)
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Funders
  • National Science Foundation (12192223, 11933007, SEV-2017-0709, 1265383, 1818253, 1743442, 11991053, DEAC05- 00OR22725, 1221421, 1715061, ACI-1 548 562, 1548562, 00OR22725, 11991052, 11721303, 1743747, TG-AST080026N, 1935980, 0735191, 11650110427, 1716536, 10625314, 89233218CNA000001, 2034306, 610058, 11725312, 1816420, 1716327, 1852617, 12192220, 1903847)
  • Smithsonian Institution
  • U.S. Department of Energy (#89233218CNA000001, AC05-00OR22725, DE--AC05--00OR22725, DE-AC05?, Contract No. DE-AC05-00OR22725, 1548562, ACI-1548562, No. DE-AC05-00OR22725, 00OR22725)
  • National Aeronautics and Space Administration (AST-1935980, 89233218CNA000001, AST-1816420, ACI-1548562, AC05-00OR22725, DE-AC05-00OR22725, OISE-1743747, AST-2034306, AST-1716536)
  • John Templeton Foundation (AST20023, OISE-1743747)
  • Gordon and Betty Moore Foundation (IN112820, 263356, 1221421, AST-2034306, AST-1935980, Fondecyt 1221421)
  • University of Chicago
  • University of Arizona
  • Netherlands eScience Center
  • Ministerio de Ciencia, Innovación y Universidades (PID2020-117404GB-C21, SEV-2017-0709, PID2019, PGC 2018, PID2020, AYA2016-80889-P, PGC2018-098915-B-C21)
  • National Radio Astronomy Observatory
  • Associated Universities
  • Government of Canada (DE-AC05-00OR22725)
  • National Research Foundation (77948, NRF-2015H1D3A1066561, NRF-2015H1A2A1033752)
  • University of Pretoria
  • Universiteit Leiden
  • National Natural Science Foundation of China (ACI-1548562, DE-AC05-00OR22725, 11650110427, 12 192 220, 12192223, AST-2034306, AST-1935980, (11721303, 11991052, 0 and, 11873028, 11725312, 11991053, 11933007)
  • Universiteit van Amsterdam
  • Radboud Universiteit
  • Academia Sinica
  • Chinese Academy of Sciences (JCYJ-SHFY2021-013, 2017YFA0402700, AST-2034306, 11991052, 11721303, 11933007, AST-1935980)
  • China Postdoctoral Science Foundation (11991052, 2020M671266, 11721303)
  • Consejo Nacional de Ciencia y Tecnología (U0004-246083, 279006, U0004-259839, F0003-281692, M0037-279006, 263356, 104497, 281692, 275201, F0003-272050)
  • Nederlandse Organisatie voor Wetenschappelijk Onderzoek (DE-AC05-00OR22725, 639.043.513, OCENW.KLEIN.113)
  • Korea Astronomy and Space Science Institute
  • National Research Foundation of Korea (2015H1D3A1066561, 2021R1A6A3A01086420, 2022R1C1C1005255, NRF-2015H1D3A1066561, 2019H1D3A1A01102564, NRF-2015H1A2A1033752, 2019R1F1A1059721, ACI-1548562, DE-AC05-00OR22725, 2015H1A2A1033752)
  • Max-Planck-Gesellschaft (2017YFA0402700)
  • Vetenskapsrådet (01154, 2017-00648)
  • China Scholarship Council (DE-AC05-00OR22725)
  • European Southern Observatory
  • Centre National de la Recherche Scientifique
  • Ministerio de Ciencia e Innovación (AYA2016-80889-P, SEV2017-0709, PID2019, PGC2018, PGC2018-098915-B-C21, PID2019-108995GB-C21, PID2020, PID2020-117404GB-C21)
  • Shanghai Jiao Tong University
  • Universidad Nacional Autónoma de México (IN112417, IN112820, SEV-2017-0709)
  • National Astronomical Observatory of Japan
  • Recruitment Program of Global Experts
  • Junta de Andalucía (SEV-2017-0709, P18-FR-1769)
  • Instituto de Astrofísica de Andalucía (SEV‐2017‐0709)
  • Agencia Nacional de Investigación y Desarrollo (NCN19-058, Fondecyt 1221421, 1221421, DE-AC05-00OR22725)
  • Institut Périmètre de physique théorique
  • East Asian Core Observatories Association
  • Toray Science Foundation
  • Office of Science (DEAC05- 00OR22725, 89233218CNA000001, No. DE-AC05-00OR22725, ACI-1548562, AC05-00OR22725)
  • Natural Sciences and Engineering Research Council of Canada (DE-AC05-00OR22725)
  • Science and Technology Facilities Council (ST/V000268/1)
  • Japan Society for the Promotion of Science (18K13594)
  • Consejo Superior de Investigaciones Científicas (AYA2016-80889-P, 2019AEP112, SEV-2017-0709)
  • Dirección General de Asuntos del Personal Académico, Universidad Nacional Autónoma de México (IN112820, IN112417, 263356)
  • National Institutes of Natural Sciences
  • National Key Research and Development Program of China (2017YFA0402700)
  • Office of International Science and Engineering (17-43747)
  • Oak Ridge National Laboratory (AC05-00OR22725, Contract No. DE-AC05-00OR22725, DE-AC05-00OR22725)
  • Los Alamos National Laboratory (89233218CNA 000001, DE-AC05-00OR22725)
  • Compute Ontario
Topics
  • Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Astrophysical Phenomena and Observations
  • Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Radio Astronomy Observations and Technology
  • Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Pulsars and Gravitational Waves Research
Keywords
intraday variability, black hole accretion, Event Horizon Telescope, M87, Sgr A*, image reconstruction, spatial power spectrum, excess variance, very long baseline interferometry, variable sources

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