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Related papers: An adiabatic approximation for grain alignment the…

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We investigate the efficiency of interstellar polarization $p_\lambda/A_\lambda$ where $p_\lambda$ is the fractional linear polarization and $A_\lambda$ is extinction, in 16 lines of sight as a function of wavelength $\lambda$. We have used…

Astrophysics of Galaxies · Physics 2015-05-27 Masafumi Matsumura , Youko Kameura , Koji S. Kawabata , Hiroshi Akitaya , Mizuki Isogai , Munezo Seki

We present a simple and systematic procedure to determine the effective dynamics of a Brownian particle coupled to a rapidly fluctuating correlated medium, modeled as a scalar Gaussian field, under spatial confinement. The method allows us,…

Statistical Mechanics · Physics 2023-01-02 Davide Venturelli , Markus Gross

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…

Astrophysics · Physics 2009-10-30 A. Lazarian , W. G. Roberge

Paramagnetic alignment of thermally rotating oblate dust grains is studied analytically for finite ratios of grain to gas temperatures. For such ratios, the alignment of angular momentum J in respect to the grain axis of maximal inertia is…

Astrophysics · Physics 2015-06-24 A. Lazarian

The semiclassical collapse of a sphere of quantized dust is studied. A Born-Oppenheimer decomposition is performed for the wave function of the system and the semiclassical limit is considered for the gravitational part. The method of…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Roberto Casadio , Fabio Finelli , Giovanni Venturi

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

We propose estimators for dynamic second order response theory in coarse grained variables for driven out-of-equilibrium subsystems. The error is controlled through the the notion of subsystem spectral gap for the convergence of coarse…

Probability · Mathematics 2024-11-19 Fenna Müller , Max von Renesse

Magnetic fields ($\textbf{B}$) are an important factor that controls the star formation process. The leading method to observe $\textbf{B}$ is using polarized thermal emission from dust grains aligned with $\textbf{B}$. However, in dense…

Astrophysics of Galaxies · Physics 2023-06-16 Nguyen Chau Giang , Thiem Hoang , Jeong-Gyu Kim , Le Ngoc Tram

A simplified version of a classical problem in thermodynamics -- the adiabatic piston -- is discussed in the framework of kinetic theory. We consider the limit of gases whose relaxation time is extremely fast so that the gases contained on…

Chaotic Dynamics · Physics 2009-11-11 Massimo Cencini , Luigi Palatella , Simone Pigolotti , Angelo Vulpiani

It has recently been shown that turbulence in the interstellar medium (ISM) can significantly accelerate the growth of dust grains by accretion of molecules, but the turbulent gas-density distribution also plays a crucial role in shaping…

Astrophysics of Galaxies · Physics 2020-10-09 Lars Mattsson

Self-similarity of Burgers' equation with some stochastic advection is studied. In self-similar variables a stationary solution is constructed which establishes the existence of a stochastically self-similar solution for the stochastic…

Analysis of PDEs · Mathematics 2014-03-11 Wei Wang , Anthony Roberts

The approach of nonequilibrium evolution thermodynamics earlier offered is developed. It helps to describe the processes of defect formation within the adiabatic approximation. The basic equations system depends on the initial defects…

Materials Science · Physics 2015-10-23 A. V. Khomenko , D. S. Troshchenko , L. S. Metlov

Dust in the diffuse interstellar medium remains incompletely understood with regard to the structure, composition, size distribution, and alignment properties of the grains. Joint observations of reddening, starlight polarisation spectra,…

Astrophysics of Galaxies · Physics 2026-05-27 Ralf Siebenmorgen , Stefano Bagnulo , Lapo Fanciullo , Thomas Vannieuwenhuyse , Vincent Guillet

Full calculations of the evolution of grain size distribution in galaxies are in general computationally heavy. In this paper, we propose a simple model of dust enrichment in a galaxy with a simplified treatment of grain size distribution…

Astrophysics of Galaxies · Physics 2015-06-23 Hiroyuki Hirashita

We investigate the dynamics of interstellar dust particles in moderately high resolution ($512^3$ grid points) simulations of forced compressible transonic turbulence including self-gravity of the gas. Turbulence is induced by stochastic…

Astrophysics of Galaxies · Physics 2021-12-07 Lars Mattsson , Robert Hedvall

When a Hamiltonian system undergoes a stochastic, time-dependent anharmonic perturbation, the values of its adiabatic invariants as a function of time follow a distribution whose shape obeys a Fokker-Planck equation. The effective dynamics…

Classical Physics · Physics 2023-02-07 N. Boulanger , F. Buisseret , V. Dehouck , F. Dierick , O. White

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

While the problem of grain alignment was posed more than 60 years ago the quantitative model of grain alignment that can account for the observed polarization arising from aligned grains has been formulated only recently. The quantitative…

Astrophysics of Galaxies · Physics 2009-03-09 A. Lazarian

Within the approximation of dominant charging collisions the explicit microscopic calculations of the Fokker-Planck kinetic coefficients for highly-charged grains moving in plasma are performed. It is shown that due to ion absorption by…

Plasma Physics · Physics 2007-05-23 S. A. Trigger , A. G. Zagorodny

We study the relation between the models commonly used to describe the dynamics of nonresonantly pumped exciton-polariton condensates, namely the ones described by the complex Ginzburg-Landau equation, and by the open-dissipative…

Quantum Gases · Physics 2017-02-27 Nataliya Bobrovska , Michał Matuszewski