A numerical polology sampler maps ghost- and tachyon-free regions of bosonic EFT coupling spaces and finds new particle branches, including a spin-one mode in general rank-2 tensor theories.
The Extreme Spin of the Black Hole in Cygnus X-1
4 Pith papers cite this work. Polarity classification is still indexing.
4
Pith papers citing it
abstract
The compact primary in the X-ray binary Cygnus X-1 was the first black hole to be established via dynamical observations. We have recently determined accurate values for its mass and distance, and for the orbital inclination angle of the binary. Building on these results, which are based on our favored (asynchronous) dynamical model, we have measured the radius of the inner edge of the black hole's accretion disk by fitting its thermal continuum spectrum to a fully relativistic model of a thin accretion disk. Assuming that the spin axis of the black hole is aligned with the orbital angular momentum vector, we have determined that Cygnus X-1 contains a near-extreme Kerr black hole with a spin parameter a/M>0.95 (3\sigma). For a less probable (synchronous) dynamical model, we find a/M>0.92 (3\sigma). In our analysis, we include the uncertainties in black hole mass, orbital inclination angle and distance, and we also include the uncertainty in the calibration of the absolute flux via the Crab. These four sources of uncertainty totally dominate the error budget. The uncertainties introduced by the thin-disk model we employ are particularly small in this case given the extreme spin of the black hole and the disk's low luminosity.
representative citing papers
Black hole superradiance constrains the coupling strength in interacting dark energy-dark matter models through modifications to the effective mass of ultralight bosons in two scenarios.
Simulations of accreting black holes in standard and complex spacetimes indicate that magnetic geometry, quantum corrections, and binary dynamics influence flares, precession, photon rings, and multi-wavelength variability, with potential EHT constraints.
Observational evidence links obscured super-Eddington accretion to slower precessing jets in stellar-mass compact object systems, contrasting with fixed fast jets in low-density environments.
citing papers explorer
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Numerical polology: towards next-generation model-building for cosmology
A numerical polology sampler maps ghost- and tachyon-free regions of bosonic EFT coupling spaces and finds new particle branches, including a spin-one mode in general rank-2 tensor theories.
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Constraining interacting dark energy models with black hole superradiance
Black hole superradiance constrains the coupling strength in interacting dark energy-dark matter models through modifications to the effective mass of ultralight bosons in two scenarios.
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GRMHD and GRRT Simulations of Black Hole Accretion: Flares, Precession, and Complex Spacetimes
Simulations of accreting black holes in standard and complex spacetimes indicate that magnetic geometry, quantum corrections, and binary dynamics influence flares, precession, photon rings, and multi-wavelength variability, with potential EHT constraints.
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The link between obscured accretion and mildly relativistic precessing jets
Observational evidence links obscured super-Eddington accretion to slower precessing jets in stellar-mass compact object systems, contrasting with fixed fast jets in low-density environments.