On the Disalignment of Interstellar Grains
arXiv:astro-ph/0603283 · doi:10.1086/505342
Abstract
Several mechanisms have been proposed to explain the alignment of grains with the interstellar magnetic field, including paramagnetic dissipation, radiative torques, and supersonic gas-grain streaming. These must compete with disaligning processes, including randomly directed torques arising from collisions with gas atoms. I describe a novel disalignment mechanism for grains that have a time-varying electric dipole moment and that drift across the magnetic field. Depending on the drift speed, this mechanism may yield a much shorter disalignment timescale than that associated with random gas atom impacts. For suprathermally rotating grains, the new disaligning process may be more potent for carbonaceous dust than for silicate dust. This could result in efficient alignment for silicate grains but poor alignment for carbonaceous grains.
19 pages, 3 figures, submitted to ApJ
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Cited by in corpus (11)
- Tracing Magnetic Fields with Aligned Grains
- A unified model of grain alignment: radiative alignment of interstellar grains with magnetic inclusions
- Alignment of Dust with Magnetic Inclusions: Radiative Torques and Superparamagnetic Barnett and Nuclear Relaxation
- Magnetic Properties of Dust Grains, Effect of Precession and Radiative Torque Alignment
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- Alignment and rotational disruption of dust
- Interstellar polarization and grain alignment: the role of iron and silicon
- A systematic study of radiative torque grain alignment in the diffuse interstellar medium
- Two modes of carbonaceous dust alignment
- Electric dipole moments and disalignment of interstellar dust grains
- Polarized microwave emission from space particles in the upper atmosphere of the Earth