Dynamics of charged dust particles in protoplanetary discs

Abstract

We study the effect of an imposed magnetic field on the motion of charged dust particles in magnetically active regions of a protoplanetary disc. Assuming a power law structure for the vertical and the toroidal components of the magnetic field for the regions beyond magnetically dead region of the disc, the radial and the vertical velocities of the charged particles, in the asymptotic case of small particles, are calculated analytically. While grains with radii smaller than a critical radius significantly are affected by the magnetic force, motion of the particles with larger radii is independent of the magnetic field. The critical radius depends on the magnetic geometry and the charge of the grains. Assuming that a grain particle has one elementary charge and the physical properties of the disc correspond to a minimum-mass solar nebula, we show that only micron-sized grains are affected by the magnetic force. Also, charge polarity determines direction of the radial velocity. For such small particles, both the radial and the vertical velocities increase due to the magnetic force.

Accepted for publication in Astrophysics & Space Science

References in corpus (18)

• Three-dimensional MHD Simulations of Radiatively Inefficient Accretion Flows
• Planetesimal Formation by Gravitational Instability
• Radial Flow of Dust Particles in Accretion Disks
• NICMOS Imaging of the HR 4796A Circumstellar Disk
• Magnetic fields in protoplanetary disks
• Dust Migration and Morphology in Optically Thin Circumstellar Gas Disks
• On the Ionisation Fraction in Protoplanetary Disks I: Comparing Different Reaction Networks
• Self-Similar Magnetocentrifugal Disk Winds with Cylindrical Asymptotics
• Individual and collective behavior of dust particles in a protoplanetary nebula
• Dead Zones and Extrasolar Planetary Properties
• Magnetic Field Limitations on Advection Dominated Flows
• Dust Distribution in Gas Disks. A Model for the Ring Around HR 4796A
• Surface Outflow in Optically Thick Dust Disks by the Radiation Pressure
• Dust Distribution in Gas Disks II: Self Induced Ring Formation Through a Clumping Instability
• Image of Fomalhaut Dust Ring at 350 Microns: Relative Column Density Map Shows Pericenter-Apocenter Asymmetry
• The magnetorotational instability across the dead zone of protoplanetary disks
• A class of self-gravitating, magnetized accretion disks
• Scale-Free Thin Discs with an Isopedic Magnetic Field