English
Related papers

Related papers: Radiative torques: Analytical Model and Basic Prop…

200 papers

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…

Radiative torques on irregular dust grains, in addition to producing superthermal rotation, play a direct dynamical role in the alignment of interstellar dust with the local magnetic field. The equations governing the orientation of…

Astrophysics · Physics 2009-10-28 B. T. Draine , Joseph C. Weingartner

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

Dust polarization induced by aligned grains is widely used to study magnetic fields in various environments, including star-forming regions. However, the question of to what optical depth grain alignment still exists in a dense molecular…

Astrophysics of Galaxies · Physics 2021-03-03 Thiem Hoang , Le Ngoc Tram , Hyeseung Lee , Pham Ngoc Diep , Nguyen Bich Ngoc

Dust polarization depends on the physical and mechanical properties of dust, as well as the properties of local environments. To understand how dust polarization varies with grain mechanical properties and the local environment, in this…

Astrophysics of Galaxies · Physics 2020-06-17 Hyeseung Lee , Thiem Hoang , Ngan Le , Jungyeon Cho

Collisions of gas particles with a drifting grain give rise to a mechanical torque on the grain. Recent work by Lazarian & Hoang showed that mechanical torques might play a significant role in aligning helical grains along the interstellar…

Astrophysics of Galaxies · Physics 2016-02-16 Indrajit Das , Joseph C. Weingartner

We study alignment of grains by radiative torques. We found steep rise of radiative torque efficiency as grain size increases. This allows larger grains that are known to exist within molecular clouds to be aligned by the attenuated and…

Astrophysics · Physics 2009-11-11 J. Cho , A. Lazarian

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

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

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

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

Grain alignment theory suggests that grains should be aligned in circumstellar regions and the observational data available supports this conclusion. We discuss the alignment of grains via (1) magnetic relaxation, (2) mechanical processes,…

Astrophysics · Physics 2007-05-23 Lazarian A

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

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

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 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

Irregular dust grains are subject to radiative torques when irradiated by interstellar starlight. It is shown how these radiative torques may be calculated using the discrete dipole approximation. Calculations are carried out for one…

Astrophysics · Physics 2009-10-28 B. T. Draine , Joseph C. Weingartner

The polarisation of light induced by aligned interstellar dust serves as a significant tool in investigating cosmic magnetic fields, dust properties, and poses a challenge in characterising the polarisation of the cosmic microwave…

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 consider grains with superparamagnetic inclusions and report two new condensed matter effects that can enhance the internal relaxation of the energy of a wobbling grain, namely, superparamagnetic Barnett relaxation, as well as, an…

Astrophysics · Physics 2009-11-13 A. Lazarian , T. Hoang