Ambipolar Di usion : A Relaxation Technique for ConstructingForce
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چکیده
Force{Free Magnetic Fields, and Astrophysical Applications. Paul J. Dellar Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Silver Street, Cambridge, CB3 9EW, UK [email protected] http://www.damtp.cam.ac.uk/user/pjd12 Many authors have studied the interaction of a magnetic eld with an accretion disk. These thin, approximately axisymmetric structures comprise material in approximately Keplerian orbits around, and close to the equatorial plane of, a massive central object such as a star. One longstanding problem in accretion disk theory concerns the mechanism responsible for removing angular momentum from material owing in towards the central object. Without some such mechanism no in ow can occur. The most popular theory postulates a turbulent viscosity due to some elusive instability mechanism, possibly the so{called Balbus{Hawley (1991) instability in highly ionized disks. However, due to the problems associated with this conventional wisdom (one of which we discuss later) it is well worth investigating alternative approaches. θ inflow jet
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تاریخ انتشار 2008