Pith. sign in

REVIEW 8 cited by

An Unambiguous Detection of Faraday Rotation in Sagittarius A*

Not yet reviewed by Pith; the record is open.

This paper has not been read by Pith yet. Machine review is queued; the pith claim, tier, and objections will appear here once it completes.

SPECIMEN: schema-true, not a live event

T0 review · schema-true

One-sentence machine reading of the paper's core claim.

pith:XXXXXXXX · record.json · timestamp

arxiv astro-ph/0611791 v1 pith:UK7PW4WF submitted 2006-11-26 astro-ph

classification astro-ph
keywords rotationmeasuremeasurementspositionsubmillimeteraccretionanglechanges
verification ladder T0 review T1 audit T2 compute T3 formal

Signed reviews

No signed human review yet.

0 comments
read the original abstract

The millimeter/submillimeter wavelength polarization of Sgr A* is known to be variable in both magnitude and position angle on time scales down to a few hours. The unstable polarization has prevented measurements made at different frequencies and different epochs from yielding convincing measurements of Faraday rotation in this source. Here we present observations made with the Submillimeter Array polarimeter at 227 and 343 GHz with sufficient sensitivity to determine the rotation measure at each band without comparing position angles measured at separate epochs. We find the 10-epoch mean rotation measure to be (-5.6+/-0.7)x10^5 rad/m^2; the measurements are consistent with a constant value. We conservatively assign a 3sigma upper limit of 2x10^5 rad/m^2 to rotation measure changes, which limits accretion rate fluctuations to 25%. This rotation measure detection limits the accretion rate to less than 2x10^-7 M_sun/yr if the magnetic field is near equipartition, ordered, and largely radial, while a lower limit of 2x10^-9 M_sun/yr holds even for a sub-equipartition, disordered, or toroidal field. The mean intrinsic position angle is 167+/-7 degrees and we detect variations of 31(+18/-9) degrees. These variations must originate in the submillimeter photosphere, rather than arising from rotation measure changes.

Discussion (0). Continue with ORCID to comment.

Forward citations

Cited by 8 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

  1. Multifrequency Synthesis via CHIBI: Colorful Hierarchical Interferometric Bayesian Imaging

    astro-ph.IM 2026-06 unverdicted novelty 7.0 of 10

    CHIBI is a new hierarchical Bayesian method for multifrequency synthesis radio imaging based on synchrotron spectral parametrization, demonstrated on VLBA MOJAVE data and simulated EHT observations of M87*.

  2. Decoding the jet of BL Lacertae using relativistic magneto-hydrodynamics

    astro-ph.HE 2026-08 conditional novelty 6.0 of 10

    The highest optical polarization flare ever seen from a blazar is explained by a sweeping, Doppler-boosted helical jet component, and the jet appears proton-dominated.

  3. The weight of light: colliding pulses of radiation in General Relativity

    gr-qc 2026-07 conditional novelty 6.0 of 10

    Focused pulses of electromagnetic radiation can self-gravitate into black holes and, just below the collapse threshold, into ultracompact horizonless states whose measured compactness exceeds the hoop-conjecture value.

  4. A Kinematic Study of Wolf-Rayet Stars at the Galactic Center I: Binary Candidates and Constraints on the Binary Fraction

    astro-ph.GA 2026-06 unverdicted novelty 6.0 of 10

    30-year kinematic monitoring of 27 Galactic center Wolf-Rayet stars identifies five binary candidates and infers a binary fraction of 0.56 ± 0.18.

  5. Gravitational Waves from Accretion Disks: Turbulence, Mode Excitation and Prospects for Future Detectors

    gr-qc 2025-02 conditional novelty 6.0 of 10

    Turbulent accretion disks can stochastically excite black hole quasinormal ringing, but the resulting gravitational-wave background is below the reach of near-term detectors.

  6. Chaotic behaviors of particles around the black hole with an anisotropic matter immersed in a magnetic field

    gr-qc 2026-07 unverdicted novelty 4.0 of 10

    Exact black hole solution with anisotropic matter and magnetic field shows the matter parameter reduces local chaos (Lyapunov exponent) while the magnetic field drives qualitative shifts in global chaos (Poincaré sections).

  7. Investigating the interplay of the braneworld gravity and the plasma environment on the black hole shadow

    gr-qc 2025-12 unverdicted novelty 4.0 of 10

    Negative tidal charge enlarges the shadow of rotating braneworld black holes while inhomogeneous plasma shrinks it and homogeneous plasma enlarges it; EHT data limits q to roughly -1.15 to 0.45 for M87* in the low-den...

  8. M87: a cosmic laboratory for deciphering black hole accretion and jet formation

    astro-ph.HE 2024-12 unverdicted novelty 1.0 of 10

    A comprehensive review of M87's black hole, accretion flow, and jet observations from event-horizon to kiloparsec scales, with no new measurements.

Pith tools