Generation of dynamo magnetic fields in thin Keplerian disks

Abstract

view Abstract Citations (40) References (32) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Generation of Dynamo Magnetic Fields in Thin Keplerian Disks Stepinski, T. F. ; Levy, E. H. Abstract The combined action of nonuniform rotation and helical convection in protoplanetary disks, in the Galaxy, or in accretion disks surrounding black holes and other compact objects, enables an alpha-omega dynamo to generate a large-scale magnetic field. In this paper, the properties of such magnetic fields are investigated using a two-dimensional, partially numerical method. The structures of the lowest-order steady state and oscillatory modes are calculated for two kinds of external boundary conditions. A quadruple, steady state, highly localized mode is the most easily excited for low values of the dynamo number. The results indicate that, except under special conditions, disk dynamo modes tend to consist of relatively localized rings structures. For large values of the dynamo number, the magnetic field consists of a number of quasi-independent, spatially localized modes generated in various concentric rings filling the disk inward of a dynamo generation 'front'. Publication: The Astrophysical Journal Pub Date: October 1990 DOI: 10.1086/169268 Bibcode: 1990ApJ...362..318S Keywords: Accretion Disks; Black Holes (Astronomy); Dynamo Theory; Interstellar Magnetic Fields; Kepler Laws; Boundary Conditions; Milky Way Galaxy; Rotating Disks; Steady State; Astrophysics; ACCRETION; HYDROMAGNETICS full text sources ADS |