Alignment and rotational disruption of dust

Abstract

We reveal a deep connection between alignment of dust grains by RAdiative torques (RATs) and MEchanical Torques (METs) and rotational disruption of grains introduced by Hoang et al. (2019). The disruption of grains happens if they have attractor points corresponding to high angular momentum (high-J). We introduce {\it fast disruption} for grains that are directly driven to the high-J attractor on a timescale of spin-up, and {\it slow disruption} for grains that are first moved to the low-J attractor and gradually transported to the high-J attractor by gas collisions. The enhancement of grain magnetic susceptibility via iron inclusions expands the parameter space for high-J attractors and increases percentage of grains experiencing the disruption. The increase in the magnitude of RATs or METs can increase the efficiency of fast disruption, but counter-intuitively, decreases the effect of slow disruption by forcing grains towards low-J attractors, whereas the increase in gas density accelerates disruption by faster transporting grains to the high-J attractor. We also show that disruption induced by RATs and METs depends on the angle between the magnetic field and the anisotropic flow. We find that pinwheel torques can increase the efficiency of {\it fast disruption} but may decrease the efficiency of {\it slow disruption} by delaying the transport of grains from the low-J to high-J attractors via gas collisions. The selective nature of the rotational disruption opens a possibility of observational testing of grain composition as well as physical processes of grain alignment.

32 pages, 14 figures. Accepted to ApJ

References in corpus (19)

• Theory of Star Formation
• Radiative torques: Analytical Model and Basic Properties
• The Carnegie Supernova Project: Intrinsic Colors of Type Ia Supernovae
• Radiative torque alignment: Essential Physical Processes
• Grain Alignment by Radiative Torques in Special Conditions and Implications
• Subsonic Mechanical Alignment of Irregular Grains
• Radiative torques alignment in the presence of pinwheel torques
• Alignment of Dust with Magnetic Inclusions: Radiative Torques and Superparamagnetic Barnett and Nuclear Relaxation
• Properties of extragalactic dust inferred from linear polarimetry of Type Ia Supernovae
• The Carnegie Supernova Project-I: Correlation Between Type Ia Supernovae and Their Host Galaxies from Optical to Near-Infrared Bands
• Turbulence Spectra from Spectral Lines: Tests of the Velocity Channel Analysis and Velocity Coordinate Spectrum Techniques
• Radiative torques of irregular grains: Describing the alignment of a grain ensemble
• Understanding polarized dust emission from $\rho$ Ophiuchi A in light of grain alignment and disruption by radiative torques
• On the Disalignment of Interstellar Grains
• Two modes of carbonaceous dust alignment
• Thermal Flipping of Interstellar Grains
• Effects of rotational disruption on the evolution of grain size distribution in galaxies
• Evolution of Dust and Water Ice in Cometary Comae by Radiative Torques
• Barnett relaxation in non-symmetric grains

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• Grain alignment and dust evolution physics with polarisation (GRADE-POL). I. Dust polarisation modelling for isolated starless cores
• Effect of dust rotational disruption by radiative torques on radiation pressure feedback from massive protostars