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Related papers: Radiative torque alignment: Essential Physical Pro…

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The linear polarization of thermal dust emission provides a powerful tool to probe interstellar and circumstellar magnetic fields, because aspherical grains tend to align themselves with magnetic field lines. While the Radiative Alignment…

Aims. It is quintessential for the analysis of the observed dust polarization signal to understand the rotational dynamics of interstellar dust grains. Additionally, high rotation velocities may rotationally disrupt the grains, which…

Astrophysics of Galaxies · Physics 2024-12-23 Jonathan A. Jäger , Stefan Reissl , Ralf S. Klessen

Dust clouds are ubiquitous in the atmospheres of hot Jupiters and affect their observable properties. The alignment of dust grains in the clouds and resulting dust polarization is a promising method to study magnetic fields of exoplanets.…

Earth and Planetary Astrophysics · Physics 2021-08-24 Thiem Hoang , A. Lazarian

We study the internal and external alignment of carbonaceous grains, including graphite and hydrogenated amorphous carbon (HAC), in the interstellar medium (ISM) within the RAdiative Torque (RAT) paradigm. For internal alignment (IA), we…

Astrophysics of Galaxies · Physics 2023-01-20 Thiem Hoang , Vo Hong Minh Phan , Le Ngoc Tram

Aligned grains provide one of the easiest ways to study magnetic fields in diffuse gas and molecular clouds. How reliable our conclusions about the inferred magnetic field depends critically on our understanding of the physics of grain…

Astrophysics · Physics 2008-11-26 Lazarian A

We study the alignment of grains subject to both radiative torques and pinwheel torques while accounting for thermal flipping of grains. By pinwheel torques we refer to all systematic torques that are fixed in grain body axes, including the…

Astrophysics · Physics 2009-06-23 T. Hoang , A. Lazarian

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

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

It is shown that mechanical alignment of grains can be efficient for grains rotating suprathermally, i.e. with kinetic energy substantially exceeding $k$ (the Boltzmann constant) over any temperature in the system. The paper studies…

Astrophysics · Physics 2009-10-28 A. Lazarian

Modern understanding of dust astrophysics reveals that RAdiative Torques (RATs) arising from the radiation-dust interaction can induce two fundamental effects, including grain alignment and rotational disruption. Here we review the recent…

Astrophysics of Galaxies · Physics 2022-09-16 Le Ngoc Tram , Thiem Hoang

The alignment of interstellar dust grains with magnetic fields provides a key method for measuring the strength and morphology of the fields. In turn, this provides a means to study the role of magnetic fields from diffuse gas to dense…

Astrophysics of Galaxies · Physics 2016-02-09 John E. Vaillancourt , B-G Andersson

This paper provides a quantitative account of a recently introduced mechanism of mechanical alignment of suprathermally rotating grains. These rapidly rotating grains are essentially not susceptible to random torques arising from gas-grain…

Astrophysics · Physics 2009-10-28 Alex Lazarian , Michael Efroimsky

We study the alignment and rotational disruption of dust grains at the centre of our Galaxy using polarized thermal dust emission observed by SOFIA/HAWC+ and JCMT/SCUPOL at 53, 216, and 850 $\mu$m. We analyzed the relationship between the…

Astrophysics of Galaxies · Physics 2023-05-01 M. S. Akshaya , Thiem Hoang

Polarized emission from interstellar dust grains is commonly used to infer information about the underlying magnetic field from the diffuse interstellar medium to molecular cloud cores. Therefore, the ability to accurately determine…

Solar and Stellar Astrophysics · Physics 2026-02-19 Marco Leon Scheiter , Sebastian Wolf

Context. Planck observations demonstrated that the grain alignment efficiency is almost constant in the diffuse ISM. Aims. We test if the Radiative Torque (RAT) theory is compatible with observational constraints on grain alignment.…

Instrumentation and Methods for Astrophysics · Physics 2020-08-26 Stefan Reissl , Vincent Guillet , Robert Brauer , François Levrier , François Boulanger , Ralf S. Klessen

Interstellar grain alignment studies are currently experiencing a renaissance due to the development of a new quantitative theory based on Radiative Alignment Torques (RAT). One of the distinguishing predictions of this theory is a…

Astrophysics of Galaxies · Physics 2015-05-30 B-G Andersson , O. Pintado , S. B. Potter , V. Straizys , M. Charcos-Llorens

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

It is shown, that mechanical alignment can be efficient for suprathermally rotating grains, provided that they drift with supersonic velocities. Such a drift should be widely spread due to both Alfv\'{e}nic waves and ambipolar diffusion.…

Astrophysics · Physics 2015-06-24 A. Lazarian

Magnetic fields play a crucial role in various astrophysical processes, including star formation, accretion of matter, transport processes (e.g., transport of heat), and cosmic rays. One of the easiest ways to determine the magnetic field…

Astrophysics · Physics 2009-11-13 A. Lazarian

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