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Cosmology, Relativity, and Gravity Commons™
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Articles 1 - 3 of 3
Full-Text Articles in Cosmology, Relativity, and Gravity
Possible Evolution Of Supermassive Black Holes From Fri Quasars, Matthew I. Kim, Damian J. Christian, David Garofalo, Jaclyn D'Avanzo
Possible Evolution Of Supermassive Black Holes From Fri Quasars, Matthew I. Kim, Damian J. Christian, David Garofalo, Jaclyn D'Avanzo
Faculty and Research Publications
We explore the question of the rapid buildup of black hole mass in the early universe employing a growing black hole mass-based determination of both jet and disc powers predicted in recent theoretical work on black hole accretion and jet formation. Despite simplified, even artificial assumptions about accretion and mergers, we identify an interesting low probability channel for the growth of one billion solar mass black holes within hundreds of millions of years of the big bang without appealing to super Eddington accretion. This result is made more compelling by the recognition of a connection between this channel and an …
Modeling The Galactic Center Nonthermal Filaments As Magnetized Wakes, Russell B. Dahlburg, Giorgio Einaudi, Ted N. La Rosa, Steven N. Shore
Modeling The Galactic Center Nonthermal Filaments As Magnetized Wakes, Russell B. Dahlburg, Giorgio Einaudi, Ted N. La Rosa, Steven N. Shore
Faculty and Research Publications
We simulate the Galactic center nonthermal laments as magnetized wakes formed dynamically from amplification of a weak ( tens of l G) global magnetic field through the interaction of molecular clouds with a Galactic center wind. One of the key issues in this cometary model is the stability of the lament against dynamical disruption. Here we show two-dimensional MHD simulations for interstellar conditions that are appropriate for the Galactic center. The structures eventually disrupt through a shear-driven nonlinear instability but maintain coherence for lengths up to 100 times their width as observed. The final instability, which destroys the lament through …
New Promise For Electron Bulk Energization In Solar Flares: Preferential Fermi Acceleration Of Electrons Over Protons In Reconnection-Driven Magnetohydrodynamic Turbulence, Ted La Rosa, Ronald L. Moore, James A. Miller, Steven N. Shore
New Promise For Electron Bulk Energization In Solar Flares: Preferential Fermi Acceleration Of Electrons Over Protons In Reconnection-Driven Magnetohydrodynamic Turbulence, Ted La Rosa, Ronald L. Moore, James A. Miller, Steven N. Shore
Faculty and Research Publications
The hard X-ray luminosity of impulsive solar flares indicates that electrons in the low corona are bulk energized to energies of order 25 keV. LaRosa & Moore pointed out that the required bulk energization could be produced by cascading MHD turbulence generated by Alfvénic outflows from sites of strongly driven reconnection. LaRosa, Moore, & Shore proposed that the compressive component of the cascading turbulence dissipates into the electrons via Fermi acceleration. However, for this to be a viable electron bulk energization mechanism, the rate of proton energization by the same turbulence cannot exceed the electron energization rate. In this paper …