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The Scattering and Intrinsic Structure of Sagittarius A* at Radio Wavelengths
Open accessAbstract
Radio images of the Galactic Center supermassive black hole, Sagittarius A* (Sgr A*), are dominated by interstellar scattering. Previous studies of Sgr A* have adopted an anisotropic Gaussian model for both the intrinsic source and the scattering, and they have extrapolated the scattering using a purely λ 2 scaling to estimate intrinsic properties. However, physically motivated source and scattering models break all three of these assumptions. They also predict that refractive scattering effects will be significant, which have been ignored in standard model fitting procedures. We analyze radio observations of Sgr A* using a physically motivated scattering model, and we develop a prescription to incorporate refractive scattering uncertainties when model fitting. We show that an anisotropic Gaussian scattering kernel is an excellent approximation for Sgr A* at wavelengths longer than 1 cm, with an angular size of along the major axis, along the minor axis, and a position angle of . We estimate that the turbulent dissipation scale is at least 600 km, with tentative support for r in = 800 ± 200 km, suggesting that the ion Larmor radius defines the dissipation scale. We find that the power-law index for density fluctuations in the scattering material is β < 3.47, shallower than expected for a Kolmogorov spectrum ( β = 11/3), and we estimate in the case of r in = 800 km. We find that the intrinsic structure of Sgr A* is nearly isotropic over wavelengths from 1.3 mm to 1.3 cm, with a size that is roughly proportional to wavelength: . We discuss implications for models of Sgr A*, for theories of interstellar turbulence, and for imaging Sgr A* with the Event Horizon Telescope.
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“Second, signi fi cant refractive scattering in the interstellar medium produces additional substructure within the image that is not present in the intrinsic emission map”
From First Sagittarius A* Event Horizon Telescope Results. IV. Variability, Morphology, and Black Hole Mass (2022) · cites this paper as Johnson et al. 2018
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Cites
Interferometry and Synthesis in Radio Astronomy
Thompson, A., Moran, J. M., & Swenson, G. W. (2017) · Astronomy and astrophysics library · doi:10.1007/978-3-319-44431-4 · Cited by 2,416
Self-citationToward a theory of interstellar turbulence. 2: Strong alfvenic turbulence
Goldreich, P., & Sridhar, S. (1995) · The Astrophysical Journal · doi:10.1086/175121 · Cited by 2,250
Relativistic jets as compact radio sources
Blandford, R. D., & Königl, A. (1979) · The Astrophysical Journal · doi:10.1086/157262 · Cited by 2,058
Inertial-Range Spectrum of Hydromagnetic Turbulence
Kraichnan, R. H. (1965) · The Physics of Fluids · doi:10.1063/1.1761412 · Cited by 1,737
Hot Accretion Flows Around Black Holes
Yuan, F., & Narayan, R. (2014) · Annual Review of Astronomy and Astrophysics · doi:10.1146/annurev-astro-082812-141003 · Cited by 1,529
Self-citationGRAVITY Collaboration, Abuter, R., Amorim, A., Anugu, N., Bauböck, M., Benisty, M., Berger, J. P., Blind, N., Bonnet, H., Brandner, W., et al. (2018) · Astronomy & Astrophysics · doi:10.1051/0004-6361/201833718 · Cited by 946
Self-citationElectron density power spectrum in the local interstellar medium
Armstrong, J. W., Rickett, B. J., & Spangler, S. R. (1995) · The Astrophysical Journal · doi:10.1086/175515 · Cited by 928
Event-horizon-scale structure in the supermassive black hole candidate at the Galactic Centre
Doeleman, S. S., Weintroub, J., Rogers, A. E. E., Plambeck, R. L., Freund, R. W., Tilanus, R. P. J., Friberg, P., Ziurys, L. M., Moran, J. M., Corey, B. E., et al. (2008) · Nature · doi:10.1038/nature07245 · Cited by 836
Self-citationRadio Propagation Through the Turbulent Interstellar Plasma
Rickett, B. J. (1990) · Annual Review of Astronomy and Astrophysics · doi:10.1146/annurev.aa.28.090190.003021 · Cited by 739
Greisen, E. W. (2003) · Springer eBooks · doi:10.1007/0-306-48080-8_7 · Cited by 722
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Research works printed but not linked: 6
- Celnikier, 1983, A&A, 126, 293
- Falcke, 2000, A&A, 362, 113
- Iroshnikov, 1964, SvA, 7, 566
- Krichbaum, 1998, A&A, 335, L106
- Krichbaum, 1993, A&A, 274, L37
- Psaltis, 2018, ApJ
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Chen, M., Crew, G., Bintley, D., Roy, A., Asada, K., Han, J., Liu, K., Chang, C.-S., McClöskey, A., Song, Y., et al. (2026) · Publications of the Astronomical Society of the Pacific · doi:10.1088/1538-3873/ae92b6
Self-citationDark matter deformations of photon-ring echoes in horizon-scale interferometryPreprint
Fathi, M. (2026) · SSRN Electronic Journal · doi:10.2139/ssrn.7355386
NeuralDMD: Interpretable Neural Representation of Dynamics from Sparse and Noisy Measurements
SaraerToosi, A., Tu, R., Lin, E. Y. H., Azizzadenesheli, K., & Levis, A. (2026) · Lecture notes in computer science · doi:10.1007/978-3-032-37447-9_1
Marazzo-Nowicki, B. J., Tiede, P., Chang, D. O., Palumbo, D. C. M., & Johnson, M. D. (2026) · The Astrophysical Journal · doi:10.3847/1538-4357/ae9d68
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Metadata
- Authors
- Johnson, M. D., Narayan, R., Psaltis, D., Blackburn, L., Kovalev, Y. Y., Gwinn, C. R., Zhao, G.-Y., Bower, G. C., Moran, J. M., Kino, M., Kramer, M., Akiyama, K., Dexter, J., Broderick, A. E., & Sironi, L.
- Affiliations
- Center for Astrophysics Harvard & Smithsonian (US)
- University of Arizona (US)
- P.N. Lebedev Physical Institute of the Russian Academy of Sciences (RU)
- University of California, Santa Barbara (US)
- Korea Astronomy and Space Science Institute (KR)
- Institute of Astronomy and Astrophysics, Academia Sinica (TW)
- Kogakuin University (JP)
- Massachusetts Institute of Technology (US)
- Max Planck Institute for Extraterrestrial Physics (DE)
- University of Waterloo (CA)
- Columbia University (US)
- Corresponding author
- Johnson, Michael D.
- ORCID
- Venue
- The Astrophysical Journal
- Publisher
- American Astronomical Society
- Published
- 2018-09-27
- Volume
- 865
- Issue
- 2
- Pages
- 104
- ISSN
- 0004-637X (ISSN-L)
- 1538-4357
- OpenAlex
- W2889248467
- Cited by
- 105
- References
- 90
- Citations by year
- 2026: 8 · 2025: 9 · 2024: 13 · 2023: 12 · 2022: 22 · 2021: 10 · 2020: 9 · 2019: 19 · 2018: 3
- FWCI
- 5.50
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Licence
- Locations
- The Astrophysical Journal (publishedVersion)
- arXiv (Cornell University) (submittedVersion)
- Research Explorer (The University of Manchester) (submittedVersion, other-oa)
- MPG.PuRe (Max Planck Society) (submittedVersion)
- arXiv (Cornell University)
- Funders
- National Science Foundation (1440254, 1312651, 1716536)
- John Templeton Foundation
- Gordon and Betty Moore Foundation (GBMF5278, AST-1440254)
- Harvard University
- Swinburne University of Technology
- Science and Technology Facilities Council (ST/P000649/1)
- Japan Society for the Promotion of Science (18K03656)
- Russian Academy of Sciences
- Topics
- Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Astrophysical Phenomena and Observations
- Physical Sciences › Physics and Astronomy › Nuclear and High Energy Physics › Astrophysics and Cosmic Phenomena
- Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Radio Astronomy Observations and Technology
- Keywords
- Sgr A*, Galactic center supermassive black hole, radio wave scattering, refractive scattering, interstellar turbulence, density fluctuations, ion Larmor radius, wavelength scaling
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