Sagittarius A* Polarization: No Advection-dominated Accretion Flow, Low Accretion Rate, and Nonthermal Synchrotron Emission
Open accessAbstract
The recent detection of polarized radiation from Sgr A* requires a nonthermal electron distribution for the emitting plasma. The Faraday rotation measure must be small, placing strong limits on the density and magnetic field strength. We show that these constraints rule out advection-dominated accretion flow models. We construct a simple two-component model that can reproduce both the radio-to-millimeter spectrum and the polarization. This model predicts that the polarization should rise to nearly 100% at shorter wavelengths. The first component, possibly a black hole-powered jet, is compact, low density, and self-absorbed near 1 mm with ordered magnetic field, relativistic Alfvén speed, and a nonthermal electron distribution. The second component is poorly constrained, but may be a convection-dominated accretion flow with ~ 10 -9 M ☉ yr -1 , in which feedback from accretion onto the black hole suppresses the accretion rate at large radii. The black hole shadow should be detectable with submillimeter VLBI.
Integrity signals
Registry
Cites
Statistics
Claims the paper makes
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
Different theoretical models for the accretion flow produce an accretion rate in the range of 10^-9-10^-8 M⊙/yr.
“Different theoretical models for the accretion flow 9 produce an accretion rate in the range of 10 -9 -10 -8 M ⊙ yr -1 (Agol 2000; Quataert & Gruzinov 2000; Yuan et al. 2004; Marrone et al. 2007; Sharma et al. 2007).”
From The Fermi/eROSITA bubbles: a look into the nuclear outflow from the Milky Way (2024) · cites this paper as Agol 2000
Cited by
Sorted by citations
An Unambiguous Detection of Faraday Rotation in Sagittarius A*
Marrone, D. P., Moran, J. M., Zhao, J.-H., & Rao, R. (2007) · The Astrophysical Journal · doi:10.1086/510850 · Cited by 298 · see citing works
On the Nature of the Variable Infrared Emission from Sagittarius A*
Yuan, F., Quataert, E., & Narayan, R. (2004) · The Astrophysical Journal · doi:10.1086/383117 · Cited by 183 · see citing works
The Fermi/eROSITA bubbles: a look into the nuclear outflow from the Milky Way
Sarkar, K. C. (2024) · The Astronomy and Astrophysics Review · doi:10.1007/s00159-024-00152-1 · Cited by 34 · see citing works
“Different theoretical models for the accretion flow 9 produce an accretion rate in the range of 10 − 9 − 10 − 8 M ⊙ yr − 1 (Agol 2000; Quataert & Gruzinov 2000; Yuan et al. 2004; Marrone et al. 2007; Sharma et al. 2007).”
BackgroundClues to the origin of Fermi bubbles from O viii/O vii line ratio
Sarkar, K. C., Nath, B. B., & Sharma, P. (2017) · Monthly Notices of the Royal Astronomical Society · doi:10.1093/mnras/stx314 · Cited by 30 · see citing works
- Authors
- Agol, E.
- Affiliations
- Johns Hopkins University (US)
- Corresponding author
- Agol, Eric
- ORCID
- Agol, Eric
- Venue
- The Astrophysical Journal
- Publisher
- American Astronomical Society
- Published
- 2000-08-01
- Volume
- 538
- Issue
- 2
- Pages
- L121-L124
- ISSN
- 0004-637X (ISSN-L)
- OpenAlex
- W2062803596
- Cited by
- 122
- References
- 0
- Citations by year
- 2026: 2 · 2025: 2 · 2024: 6 · 2023: 5 · 2022: 3 · 2021: 4 · 2020: 5 · 2019: 6 · 2018: 3 · 2017: 2 · 2016: 2 · 2015: 3 · 2014: 2 · 2013: 3 · 2012: 3
- FWCI
- 7.18
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Locations
- The Astrophysical Journal (publishedVersion)
- arXiv (Cornell University) (submittedVersion)
- CERN Document Server (European Organization for Nuclear Research) (submittedVersion)
- arXiv (Cornell University)
- 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 › Pulsars and Gravitational Waves Research
- Keywords
- Sgr A*, advection-dominated accretion flow, nonthermal electron distribution, synchrotron radiation, Faraday rotation, accretion rate, black hole shadow, two-component model
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
