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Physical Sciences and Mathematics Commons™
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Full-Text Articles in Physical Sciences and Mathematics
The Event Horizon Of M87, Avery E. Broderick, Ramesh Narayan, John Kormendy, Eric S. Perlman, Marcia J. Rieke, Sheperd S. Doleman
The Event Horizon Of M87, Avery E. Broderick, Ramesh Narayan, John Kormendy, Eric S. Perlman, Marcia J. Rieke, Sheperd S. Doleman
Aerospace, Physics, and Space Science Faculty Publications
The 6 x 10⁹ M⊙ supermassive black hole at the center of the giant elliptical galaxy M87 powers a relativistic jet. Observations at millimeter wavelengths with the Event Horizon Telescope have localized the emission from the base of this jet to angular scales comparable to the putative black hole horizon. The jet might be powered directly by an accretion disk or by electromagnetic extraction of the rotational energy of the black hole. However, even the latter mechanism requires a confining thick accretion disk to maintain the required magnetic flux near the black hole. Therefore, regardless of the jet mechanism, the …
New Constraints On Quantum Gravity From X-Ray And Gamma-Ray Observations, Eric S. Perlman, Saul A. Rappaport, Wayne A. Christiansen, Yeejack Ng, John G. Devore, David A. Pooley
New Constraints On Quantum Gravity From X-Ray And Gamma-Ray Observations, Eric S. Perlman, Saul A. Rappaport, Wayne A. Christiansen, Yeejack Ng, John G. Devore, David A. Pooley
Aerospace, Physics, and Space Science Faculty Publications
One aspect of the quantum nature of spacetime is its “foaminess” at very small scales. Many models for spacetime foam are defined by the accumulation power α, which parameterizes the rate at which Planck-scale spatial uncertainties (and the phase shifts they produce) may accumulate over large path lengths. Here α is defined by the expression for the path-length fluctuations, dℓ, of a source at distance ℓ, wherein dℓ ℓ1-aℓ a P , with ℓP being the Planck length. We reassess previous proposals to use astronomical observations of distant quasars and active galactic nuclei to test models of spacetime foam. …