Astron. Astrophys. 358, 612-616 (2000)

Accretion disk structure of adiabatic and magnetised CTTS-systems

D. Elstner and G. Rüdiger

Astrophysikalisches Institut Potsdam, An der Sternwarte 16, 14482 Potsdam, Germany

Received 10 March 2000 / Accepted 7 April 2000

Abstract

The role of a large-scale magnetic field in a classical TTS star-disk system is studied. The central object yields a magnetic dipolar field which is modified and amplified by the accretion disk. The entropy in the equatorial plane is assumed as unchanged by the magnetic field. The disk halo is considered as a plasma with the same conductivity as the disk and corotating with the star. The induced toroidal fields are confirming a former estimate by Campbell (1992); their (vertical) angular momentum transport strictly changes the accretion disk structure. For rather weak magnetic fields there is no disk inside the corotation radius, but outside the corotation radius the disk becomes much warmer, thicker and more massive than the corresponding nonmagnetic solutions. For stellar magnetic field exceeding 2000 Gauss we find the maximal magnetic torque starting to saturate.

Key words: accretion, accretion disks Magnetohydrodynamics (MHD) stars: formation

Send offprint requests to: D. Elstner (delstner@aip.de)

This article contains no SIMBAD objects.

Contents

• 1. Motivation
• 2. Basic equations
  • 2.1. Magnetic field
  • 2.2. Disk equations
• 3. Results
• 4. Discussion
• References

© European Southern Observatory (ESO) 2000

Online publication: June 8, 2000
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