Open AccessDisc structure around strongly magnetic accretors: a full disc solution with turbulent diffusivity
Author(s) -
Campbell C. G.,
Heptinstall P. M.
Publication year - 1998
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.1998.01576.x
Subject(s) - physics , magnetic diffusivity , opacity , magnetic field , magnetohydrodynamics , astrophysics , magnetic pressure , scattering , turbulence , angular momentum , accretion (finance) , radiation pressure , radius , instability , rotation (mathematics) , turbulent diffusion , mechanics , classical mechanics , optics , magnetization , geometry , computer security , mathematics , quantum mechanics , computer science
The problem of the effect of a strongly magnetic star on a surrounding accretion disc is considered. For stellar rotation periods greater than a critical value, a numerical solution is found for a steady disc with turbulent magnetic diffusion, including electron scattering opacity and radiation pressure. Inside the corotation radius, the extraction of disc angular momentum by magnetic coupling to the star becomes strong and this leads to enhanced viscous stress and dissipation. The resulting elevated temperature causes electron scattering opacity and radiation pressure to become significant further from the star than in the absence of its magnetic field. The disc ends as its height increases rapidly due to the large central pressure, its density decreases and magnetically induced viscous instability occurs.