Barnett Relaxation in Thermally-Rotating Grains
arXiv:astro-ph/9702138 · doi:10.1086/304309
Abstract
We present an exact formulation of the physics of Barnett relaxation. Our formulation is based on a realistic kinetic model of the relaxation mechanism which includes the alignment of the grain angular momentum in body coordinates by Barnett dissipation, disalignment by thermal fluctuations, and coupling of the angular momentum to the gas via gas damping. We solve the Fokker-Planck equation for the measure of internal alignment using numerical integration of the equivalent Langevin equation for Brownian rotation. The accuracy of our results is calibrated by comparing our numerical solutions with exact analytic results obtained for special cases.We describe an analytic approximation for the measure of alignment which fits our numerical results for cases of practical interest.
17 pages, 5 figures. Accepted to ApJ.
References in corpus (1)
Cited by in corpus (58)
- Radiative torques: Analytical Model and Basic Properties
- Tracing Magnetic Fields with Aligned Grains
- Radiative torque alignment: Essential Physical Processes
- Radiative transfer with POLARIS: I. Analysis of magnetic fields through synthetic dust continuum polarization measurements
- A unified model of grain alignment: radiative alignment of interstellar grains with magnetic inclusions
- Magnetic Fields via Polarimetry: Progress of Grain Alignment Theory
- Radiative grain alignment in protoplanetary disks: Implications for polarimetric observations
- Grain Alignment by Radiative Torques in Special Conditions and Implications
- On the efficiency of grain alignment in dark clouds
- Improving the model of emission from spinning dust: effects of grain wobbling and transient spin-up
- Spinning dust emission: the effect of rotation around a non-principal axis
- Grain alignment induced by radiative torques: effects of internal relaxation of energy and complex radiation fields
- Grain Alignment by Radiation in Dark Clouds and Cores
- Nuclear Spin Relaxation within Interstellar Grains
- Alignment of Irregular Grains by Mechanical Torques
- Resonance Paramagnetic Relaxation and Alignment of Small Grains
- Radiative torques alignment in the presence of pinwheel torques
- Alignment of Dust with Magnetic Inclusions: Radiative Torques and Superparamagnetic Barnett and Nuclear Relaxation
- Radiative Torques on Interstellar Grains. III. Dynamics with Thermal Relaxation
- Spinning Dust Emission: Effects of irregular grain shape, transient heating and comparison with WMAP results
- Thermal Flipping and Thermal Trapping -- New Elements in Dust Grain Dynamics
- Polarization of Magnetic Dipole Emission and Spinning Dust Emission from Magnetic Nanoparticles
- Davis-Greenstein alignment of oblate spheroidal grains
- Constraint on the Polarization of Electric Dipole Emission from Spinning Dust
- Circular polarization in comets: Observations of Comet C/1999 S4 (LINEAR) and tentative interpretation
- Disorientation of Suprathermally Rotating Grains and Grain Alignment Problem
- Spinning dust emission from ultrasmall silicates: emissivity and polarization spectrum
- On Internal and External Alignment of Dust Grains in Protostellar Environments
- Magnetic Properties of Dust Grains, Effect of Precession and Radiative Torque Alignment
- Paramagnetic alignment of small grains: a novel method for measuring interstellar magnetic fields
- Radiative torques of irregular grains: Describing the alignment of a grain ensemble
- Alignment and rotational disruption of dust
- Modeling Grain Alignment by Radiative Torques and Hydrogen Formation Torques in Reflection Nebula
- The origin of dust polarization in molecular outflows
- Predictions of polarized dust emission from interstellar clouds: spatial variations in the efficiency of radiative torque alignment
- Simulations of polarized dust emission
- On the origins of polarization holes in Bok globules
- Alignment of irregular grains by radiative torques: efficiency study
- Microwave Emission from Aligned Dust
- Physical Modeling of Dust Polarization from Magnetically Enhanced Radiative Torque (MRAT) Alignment in Protostellar Cores with POLARIS
- On the Shapes of Interstellar Grains: Modeling Extinction and Polarization by Spheroids and Continuous Distributions of Ellipsoids
- Spinning dust radiation: a review of the theory
- Stochastic oscillations of general relativistic disks
- The Mechanical Alignment of Dust (MAD) I: On the spin-up process of fractal grains by a gas-dust drift
- Polarization of Thermal Emission from Aligned Dust Grains Under an Anisotropic Radiation Field
- Detection of Polarized Infrared Emission by Polycyclic Aromatic Hydrocarbons in the MWC 1080 Nebula
- Thermal Flipping of Interstellar Grains
- Electric dipole moments and disalignment of interstellar dust grains
- Physical conditions for dust grain alignment in Class 0 protostellar cores II. The role of the radiation field in models aligning/disrupting dust grains
- Cross section alignment of polycyclic aromatic hydrocarbons by anisotropic radiation
- Spinning Dust Emission from Wobbling Grains: Important Physical Effects and Implications
- On the collisional disalignment of dust grains in illuminated and shaded regions of IC 63
- Synthetic Modelling of Polarized Dust Emission in Intermediate-Mass YSOs: I: Constraining the Role of Iron Inclusions and Inelastic Relaxation on Grain Alignment with ALMA Polarization
- Mechanical Alignment of Suprathermal Paramagnetic Cosmic-Dust Granules: the Cross-Section Mechanism
- The rotational disruption of porous dust aggregates from ab-initio kinematic calculations
- Effect of alignment on polarized infrared emission from polycyclic aromatic hydrocarbons
- Barnett relaxation in non-symmetric grains
- Grain Alignment in Molecular Clouds