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Related papers: Grain Acceleration by MHD Turbulence: Gyroresonanc…

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We investigate the gas-grain relative drift velocity distributions of charged astrophysical dust grains in MHD turbulence. We do this using a range of MHD-PIC simulations spanning different plasma-$\beta$, sonic/Alfv\'en Mach number, and…

Astrophysics of Galaxies · Physics 2025-08-28 Eric R. Moseley , Romain Teyssier

Dust grains moving at hypersonic velocities of $v_{d}\gtrsim 100\rm km~s^{-1}$ through an ambient gas are known to be destroyed by nonthermal sputtering. Yet, previous studies of nonthermal sputtering disregarded the fact that dust grains…

Astrophysics of Galaxies · Physics 2020-07-01 Thiem Hoang , Hyeseung Lee

Magnetohydrodynamic (MHD) turbulence is an important agent of energetic particle acceleration. Focusing on the compressible properties of magnetic turbulence, we adopt test particle method to study the particle acceleration from Alfv\'en,…

High Energy Astrophysical Phenomena · Physics 2021-12-08 Jianfu Zhang , Fuyuan Xiang

Turbulence is the dominant source of collisional velocities for grains with a wide range of sizes in protoplanetary disks. So far, only Kolmogorov turbulence has been considered for calculating grain collisional velocities, despite the…

Earth and Planetary Astrophysics · Physics 2021-09-01 Munan Gong , Alexei V. Ivlev , Vitaly Akimkin , Paola Caselli

Interstellar dust grains exhibit complex dynamics which is essential for understanding many key interstellar processes that involve dust, including grain alignment, grain growth, grain shattering etc. Grain rotational and translational…

Astrophysics · Physics 2007-05-23 A. Lazarian , Huirong Yan

We study the dynamics of large, charged dust grains in turbulent giant molecular clouds (GMCs). Massive dust grains behave as aerodynamic particles in primarily neutral dense gas, and thus are able to produce dramatic small-scale…

Astrophysics of Galaxies · Physics 2017-07-11 Hyunseok Lee , Philip F. Hopkins , Jonathan Squire

The presence of dust grains profoundly affects the diffusion of the magnetic field in molecular clouds. When the electrons and ions are well coupled to the magnetic field and charged grains are only indirectly coupled, emergent Hall…

Astrophysics of Galaxies · Physics 2019-02-13 B. P. Pandey , S. V. Vladimirov

In this paper, we reexamine the possibility of shear-driven turbulence during sedimentation of dust grains in the protoplanetary disk. The shear-driven turbulence is expected to occur before the onset of the gravitational instability for…

Earth and Planetary Astrophysics · Physics 2015-06-12 Yukihiko Hasegawa , Toru Tsuribe

We discuss the dynamics of dust grains subjected to uncompensated torques arising from H_2 formation. In particular, we discuss grain dynamics when a grain spins down and goes through a ``crossover''. As first pointed out by Spitzer &…

Astrophysics · Physics 2009-10-28 A. Lazarian , B. T. Draine

Collisionless, magnetized turbulence offers a promising framework for the generation of non-thermal high-energy particles in various astrophysical sites. Yet, the detailed mechanism that governs particle acceleration has remained subject to…

High Energy Astrophysical Phenomena · Physics 2022-08-17 Virginia Bresci , Martin Lemoine , Laurent Gremillet , Luca Comisso , Lorenzo Sironi , Camilia Demidem

Dust grains may be accelerated to relativistic speeds by radiation pressure, diffusive shocks, and other acceleration mechanisms. Such relativistic grains have been suggested as primary particles of ultrahigh energy cosmic rays (UHECRs). In…

Astrophysics of Galaxies · Physics 2016-05-10 Thiem Hoang , A. Lazarian , R. Schlickeiser

Thermal dust polarization is a powerful tool to probe magnetic fields ($\textbf{B}$) and grain properties. However, a systematic study of the dependence of dust polarization on grain properties in protostellar environments is not yet…

Astrophysics of Galaxies · Physics 2024-03-14 Nguyen Chau Giang , Thiem Hoang

We investigate the role and behaviour of dust grains in C-type MHD shock waves in weakly ionized, dense molecular clouds. New shock models are presented for steady, oblique C-type shock structures with shock speed v_s=18km/s, n_H=10^5cm^-3,…

Astrophysics · Physics 2009-11-11 Jacqueline F. Chapman , Mark Wardle

Context: Aligned dust grains are commonly exploited to probe the magnetic field orientation. However, the exact physical processes that result in a coherent large-scale grain alignment are far from being constrained. Aims: In this work, we…

Astrophysics of Galaxies · Physics 2023-07-05 Stefan Reissl , Paul Meehan , Ralf S. Klessen

The degree of coupling between the gas and the magnetic field during the collapse of a core and the subsequent formation of a disk depends on the assumed dust size distribution. We study the impact of grain-grain coagulation on the…

Astrophysics of Galaxies · Physics 2020-10-28 V. Guillet , P. Hennebelle , G. Pineau des Forêts , A. Marcowith , B. Commerçon , P. Marchand

We show that grains can be efficiently aligned by interacting with a subsonic gaseous flow. The alignment arises from grains having irregularities that scatter atoms with different efficiency in the right and left directions. The grains…

Astrophysics · Physics 2009-11-13 Alex Lazarian , Thiem Hoang

In a series of papers, we present a comprehensive analytic study of the global motion of growing dust grains in protoplanetary discs, addressing both the radial drift and the vertical settling of the particles. Here we study how the radial…

Earth and Planetary Astrophysics · Physics 2015-06-17 Guillaume Laibe , Jean-François Gonzalez , Sarah T. Maddison

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…

Astrophysics · Physics 2008-11-26 Joseph C. Weingartner

We study the linear growth and nonlinear saturation of the "acoustic Resonant Drag Instability" (RDI) when the dust grains, which drive the instability, have a wide, continuous spectrum of different sizes. This physics is generally…

Astrophysics of Galaxies · Physics 2021-12-13 Jonathan Squire , Stefania Moroianu , Philip F. Hopkins

We present high resolution numerical simulations of compressible magnetohydrodynamic (MHD) turbulence. We concentrate on studies of spectra and anisotropy of velocity and density. We describe a technique of separating different…

Astrophysics · Physics 2016-08-30 Jungyeon Cho , A. Lazarian