Influence of Ohmic and ambipolar heating on thermal structure of accretion discs

Abstract

We investigate dynamics of accretion discs of young stars with fossil large-scale magnetic field. Our magneto-gas-dynamic (MHD) model of the accretion discs includes equations of Shakura and Sunyaev, induction equation, equations of thermal and collisional ionization. Induction equation takes into account Ohmic and magnetic ambipolar diffusion, magnetic buoyancy. We also consider the influence of Ohmic and ambipolar heating on thermal structure of the accretion discs. We analyse the influence of considered dissipative MHD effects on the temperature of the accretion discs around classical T Tauri star. The simulations show that Ohmic and ambipolar heating operate near the borders of the region with low ionization fraction (`dead' zone). Temperature grows by $\sim 1000$ K near the inner boundary of the `dead' zone, $r\approx (0.5-1)$ au, and by $\sim 100$ K near its outer boundary, $r\approx (30-50)$ au.

8 pages, 3 figures, The Third Russian Conference on Magnetohydrodynamics, accepted for publication in a Special Issue of the Magnetohydrodynamics Journal

References in corpus (7)

• Spatially Resolved Magnetic Field Structure in the Disk of a T Tauri Star
• Fossil magnetic field of accretion disks of young stars
• An Ordered Magnetic Field in the Protoplanetary Disk of AB Aur Revealed by Mid-Infrared Polarimetry
• Theory of fossil magnetic field
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Cited by in corpus (2)

• Ohmic heating of asteroids around magnetic stars
• Dynamics of magnetized accretion disks of young stars