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Related papers: Interstellar Grain Alignment - Observational Statu…

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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

The recent detection of interstellar polarization in the solid CO feature near 4.67 micron shows that CO-mantled grains can be aligned in cold molecular clouds. These observations conflict with a theory of grain alignment which attributes…

Astrophysics · Physics 2015-06-24 A. Lazarian , W. G. Roberge

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

Polarization of starlight and thermal dust emission due to aligned non-spherical grains helps us to trace magnetic field (B-field) morphology in molecular clouds and to study grain alignment mechanisms. In this work, we study grain…

Astrophysics of Galaxies · Physics 2025-01-22 Saikhom Pravash , Archana Soam , Pham Ngoc Diep , Thiem Hoang , Nguyen Bich Ngoc , Le Ngoc Tram

The structure of magnetic fields within protostellar disks may be studied via polarimetry provided that grains are aligned in respect to magnetic field within the disks. We explore alignment of dust grains by radiative torque in T Tauri…

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

The polarization spectrum, or wavelength dependence of the polarization fraction, of interstellar dust emission provides important insights into the grain alignment mechanism of interstellar dust grains. We investigate the far-infrared…

Continuum polarization over the UV-to-microwave range is due to dichroic extinction (or emission) by asymmetric, aligned dust grains. Because of both grain alignment and scattering physics, the wavelength dependence of the polarization,…

Polarization of starlight and thermal dust emission caused by aligned dust grains is a valuable tool to characterize magnetic fields (B-fields) and constrain dust properties. However, the physics of grain alignment is not fully understood.…

Astrophysics of Galaxies · Physics 2024-09-10 Nguyen Bich Ngoc , Thiem Hoang , Pham Ngoc Diep , Le Ngoc Tram

Interstellar linear polarization occurs when starlight passes through elongated dust grains aligned by interstellar magnetic fields. The observed polarization can come from different dust structures along the line of sight (LOS). By…

We apply the theory of radiative torque (RAT) alignment for studying protoplanetary disks around a T-Tauri star and perform 3D radiative transfer calculations to provide the expected maps of polarized radiation to be compared with…

Earth and Planetary Astrophysics · Physics 2017-04-19 Ryo Tazaki , Alexandre Lazarian , Hideko Nomura

Polarized (sub)millimeter emission from dust grains in circumstellar disks was initially thought to be due to grains aligned with the magnetic field. However, higher resolution multi-wavelength observations along with improved models found…

A previous study (Paper I) investigated the polarization properties of a variety of simple convex grain shapes, some of which were found to be consistent with the observed polarization properties of interstellar dust from far-ultraviolet to…

Astrophysics of Galaxies · Physics 2025-04-07 B. T. Draine

Calculations are performed for the linear polarization of starlight due to extinction by aligned dust grains when the starlight traverses a medium with irregular magnetic fields. This medium is intended to represent the optically thick…

Astrophysics · Physics 2009-10-31 D. S. Wiebe , W. D. Watson

Paramagnetic alignment of non-spherical dust grains rotating at thermal velocities is studied. The analytical solution is found for the alignment measure of oblate grains. Perturbative approach is used for solving the problem. It is shown…

Astrophysics · Physics 2009-10-28 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

Interstellar dust grains are non-spherical and, in some environments, partially aligned along the direction of the interstellar magnetic field. Numerous alignment theories have been proposed, all of which examine the grain rotational…

Astrophysics of Galaxies · Physics 2021-03-15 Joseph C. Weingartner , Erald Kolasi , Cameron Woods

Alignment of dust by radiative torques (RATs) has proven to be the most promising mechanism to explain alignment in various astrophysical environments, from comet atmospheres to accretion disks, molecular clouds, and diffuse interstellar…

Astrophysics of Galaxies · Physics 2009-01-21 A. Lazarian , Thiem Hoang

Most astrophysical fluids are turbulent and magnetized. Fluctuations of polarization provide a promising way to study astrophysical magnetic turbulence. We discuss polarization that arises from grains and atoms aligned in respect to…

Astrophysics · Physics 2009-11-11 A. Lazarian , Huirong Yan

The optical and near-infrared (OIR) polarization of starlight is typically understood to arise from the dichroic extinction of that light by dust grains whose axes are aligned with respect to a local magnetic-field. The size distribution of…

Polarization of starlight induced by dust grains aligned with the magnetic field (hereafter B-field) is widely used to measure the two-dimensional B-fields projected onto the plane-of-sky. Here, we introduce a new method to infer…

Astrophysics of Galaxies · Physics 2025-02-04 Bao Truong , Thiem Hoang