Negative Energy And Angular Momentum Modes Of Thin Accretion Disks |
| |
Authors: | Email author" target="_blank">L?ZhangEmail author R?V?E?Lovelace |
| |
Institution: | (1) Pennsylvania State University, University Park, PA, USA;(2) Department of Astronomy, Cornell University, Ithaca, NY, USA |
| |
Abstract: | This work derives the linearized equations of motion, the Lagrangian density, the Hamiltonian density, and the canonical angular
momentum density for general perturbations ∝ exp (imφ) with m = 0, ± 1, ...] of a geometrically thin self-gravitating, homentropic fluid disk including the pressure. The theory is applied
to “eccentric,” m = ± 1 perturbations of a geometrically thin Keplerian disk. We find m = 1 modes at low frequencies relative to the Keplerian frequency. Further, it is shown that these modes can have negative
energy and negative angular momentum. The radial propagation of these low-frequency m = 1 modes can transport angular momentum away from the inner region of a disk and thus increase the rate of mass accretion.
Depending on the radial boundary conditions there can be discrete low-frequency, negative-energy, m = 1 modes. |
| |
Keywords: | accretion accretion disks – instabilities – galaxies: kinematics and dynamics |
本文献已被 SpringerLink 等数据库收录! |
|