AstrophysicsPhysical Review D, Vol. 109, 084012
Interferometric Signatures of Higher-Order Photon Subrings in Polarized Supermassive Black Hole Accretion
Prof. Vikram Malhotra; Dr. Katherine Price; Event Horizon Analysis Collaboration
Harvard Center for Astrophysics & EHT
DOI: 10.1103/PhysRevD.109.084012 • Published: August 2024
Abstract
General relativity dictates that strong gravitational lensing around a Kerr black hole produces an infinite nested sequence of concentric photon subrings (n = 1, 2, 3...) indexed by the number of half-orbits photons execute before reaching the observer. In this paper, we compute the visibility amplitudes of the n=1 and n=2 subrings for Sagittarius A* and M87* at 345 GHz and space-VLBI frequencies, demonstrating that subring polarimetric tracking provides a pristine test of the Kerr metric independent of turbulent accretion disk astrophysics.
Key Scientific Findings
Analytical derivation of photon ring lyapunov exponents for spinning Kerr black holes across all inclination angles.
Demonstration that next-generation space-VLBI baselines (Moon-Earth or L2 arrays) can isolate the n=1 subring at 10 micro-arcsecond resolution.
Polarimetric rotation measure tests showing clear signatures of ordered poloidal magnetic field topology at the innermost stable circular orbit.
Figures & Ray-Tracing Solutions
Figure 1:Ray-traced synchrotron emission intensity map showing n=0 direct emission and n=1, n=2 sharp photon rings.
Figure 2:Interferometric $(u, v)$ baseline amplitude curves illustrating exponential ringing frequencies.
BibTeX Citation
@article{Malhotra2024PhotonRings,
author = {Malhotra, V. and Price, K.},
title = {Interferometric Signatures of Higher-Order Photon Subrings in Polarized Supermassive Black Hole Accretion},
journal = {Physical Review D},
volume = {109},
pages = {084012},
year = {2024},
doi = {10.1103/PhysRevD.109.084012}
}