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Related papers: Quantitative Theory of Grain Alignment: Probing Gr…

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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 efficiency of grain alignment by radiative torques (RATs) for an ensemble of irregular grains. The grains are modeled as ensembles of oblate and prolate spheroids, deformed as Gaussian random ellipsoids, and their scattering…

Astrophysics of Galaxies · Physics 2021-06-02 Joonas Herranen , A. Lazarian , Thiem Hoang

Atacama Large Millimeter/Submillimeter Array (ALMA) has revolutionized the field of dust polarization in protoplanetary disks across multiple wavelengths. Previous observations and empirical modeling suggested multiple mechanisms of dust…

Solar and Stellar Astrophysics · Physics 2024-07-30 Nguyen Tat Thang , Pham Ngoc Diep , Thiem Hoang , Le Ngoc Tram , Nguyen Bich Ngoc , Nguyen Thi Phuong , Bao Truong

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

It is well known that the polarized continuum emission from magnetically aligned dust grains is determined to a large extent by local magnetic field structure. However, the observed significant anticorrelation between polarization fraction…

Astrophysics of Galaxies · Physics 2019-10-02 Patrick K. King , Che-Yu Chen , Laura M. Fissel , Zhi-Yun Li

We study the alignment of irregular dust grains by mechanical torques due to the drift of grains through the ambient gas. We first calculate mechanical torques (MATs) resulting from specular reflection of gas atoms for seven irregular…

Astrophysics of Galaxies · Physics 2018-01-31 Thiem Hoang , Jungyeon Cho , A. Lazarian

(Sub-)Millimeter observations of the polarized emission of aligned aspherical dust grains enable us to study the magnetic fields within protoplanetary disk. However, the interpretation of these observations is complex. One must consider the…

Solar and Stellar Astrophysics · Physics 2017-06-21 G. H. -M. Bertrang , S. Wolf

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

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

Interstellar dust grain alignment causes polarization from UV to mm wavelengths, allowing the study of the geometry and strength of the magnetic field. Over last couple of decades observations and theory have led to the establishment of the…

During the evolution of protoplanetary disks, dust grains start to grow, form larger particles, settle to the midplane, and rearrange the disk, mainly by the inward radial drift. Because of this, dust pebbles with an irregular shape usually…

Earth and Planetary Astrophysics · Physics 2025-11-05 Moritz Lietzow-Sinjen , Stefan Reissl , Mario Flock , Sebastian Wolf

How and when in the star formation sequence do dust grains start to grow into pebbles is a cornerstone question to both star and planet formation. We compute the polarized radiative transfer from a model solar-type protostellar core, using…

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

In the previous papers in this series, we found that radiative torques can play a major role in the alignment of grains with the interstellar magnetic field. Since the radiative torques can drive the grains to suprathermal rotational…

Astrophysics · Physics 2009-11-07 Joseph C. Weingartner , B. T. Draine

The radiative torque (RAT) alignment of interstellar grains with ordinary paramagnetic susceptibilities has been supported by earlier studies. The alignment of such grains depends on the so-called RAT parameter $q^{\max}$ that is determined…

Astrophysics of Galaxies · Physics 2016-11-15 Thiem Hoang , A. Lazarian

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

The polarization of starlight and thermal dust emission, resulting from non-spherical grains aligned with the interstellar magnetic field (B-field), act as a powerful tool to trace the B-field morphologies and strengths in molecular clouds…

Astrophysics of Galaxies · Physics 2026-05-26 Saikhom Pravash

Dust polarization induced by aligned non-spherical grains acts as an important tool to trace the magnetic field (B-field) morphologies and strengths in molecular clouds and constrain grain properties and their alignment mechanisms. The…

Astrophysics of Galaxies · Physics 2026-03-03 Saikhom Pravash , Thiem Hoang , Archana Soam , Qi-Lao Gu , Tie Liu , Pham Ngoc Diep , Le Ngoc Tram , Nguyen Bich Ngoc

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

Dust grains emit intrinsic polarized emission if they are elongated and aligned in the same direction. The direction of the grain alignment is determined by external forces, such as magnetic fields, radiation, and gas flow against the dust…

Earth and Planetary Astrophysics · Physics 2019-04-03 Akimasa Kataoka , Satoshi Okuzumi , Ryo Tazaki