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dc.date.accessioned2022-04-11T23:18:03Z
dc.date.available2022-04-11T23:18:03Z
dc.date.issued2022
dc.identifier.citationSatapathy, K., Psaltis, D., Özel, F., Medeiros, L., Dougall, S. T., Chan, C.-K., Wielgus, M., Prather, B. S., Wong, G. N., Gammie, C. F., Akiyama, K., Alberdi, A., Alef, W., Algaba, J. C., Anantua, R., Asada, K., Azulay, R., Baczko, A.-K., Ball, D., … Zhao, S.-S. (2022). The Variability of the Black Hole Image in M87 at the Dynamical Timescale. Astrophysical Journal.
dc.identifier.issn0004-637X
dc.identifier.doi10.3847/1538-4357/ac332e
dc.identifier.urihttp://hdl.handle.net/10150/663942
dc.description.abstractThe black hole images obtained with the Event Horizon Telescope (EHT) are expected to be variable at the dynamical timescale near their horizons. For the black hole at the center of the M87 galaxy, this timescale (5-61 days) is comparable to the 6 day extent of the 2017 EHT observations. Closure phases along baseline triangles are robust interferometric observables that are sensitive to the expected structural changes of the images but are free of station-based atmospheric and instrumental errors. We explored the day-to-day variability in closure-phase measurements on all six linearly independent nontrivial baseline triangles that can be formed from the 2017 observations. We showed that three triangles exhibit very low day-to-day variability, with a dispersion of ∼3°-5°. The only triangles that exhibit substantially higher variability (∼90°-180°) are the ones with baselines that cross the visibility amplitude minima on the u-v plane, as expected from theoretical modeling. We used two sets of general relativistic magnetohydrodynamic simulations to explore the dependence of the predicted variability on various black hole and accretion-flow parameters. We found that changing the magnetic field configuration, electron temperature model, or black hole spin has a marginal effect on the model consistency with the observed level of variability. On the other hand, the most discriminating image characteristic of models is the fractional width of the bright ring of emission. Models that best reproduce the observed small level of variability are characterized by thin ring-like images with structures dominated by gravitational lensing effects and thus least affected by turbulence in the accreting plasmas. © 2022. The Author(s). Published by the American Astronomical Society.
dc.language.isoen
dc.publisherIOP Publishing Ltd
dc.rightsCopyright © 2022. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence.
dc.rights.urihttps://creativecommons.org/licenses/by/4.0/
dc.titleThe Variability of the Black Hole Image in M87 at the Dynamical Timescale
dc.typeArticle
dc.typetext
dc.contributor.departmentAstronomy Department, University of Arizona
dc.contributor.departmentDepartment of Physics, University of Arizona
dc.contributor.departmentSteward Observatory and Department of Astronomy, University of Arizona
dc.identifier.journalAstrophysical Journal
dc.description.noteOpen access journal
dc.description.collectioninformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.
dc.eprint.versionFinal published version
dc.source.journaltitleAstrophysical Journal
refterms.dateFOA2022-04-11T23:18:03Z


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Copyright © 2022. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence.
Except where otherwise noted, this item's license is described as Copyright © 2022. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence.