相关论文: On Internal and External Alignment of Dust Grains …
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…
Earlier studies of grain alignment dealt mostly with interstellar grains that have strong internal relaxation of energy which aligns grain axis of maximum moment of inertia with respect to grain's angular momentum. In this paper, we study…
Alignment of dust grains in astrophysical environments results in the polarization of starlight as well as the polarization of radiation emitted by dust. We demonstrate the advances in grain alignment theory allow the use of linear and…
Dust grains drift through the interstellar medium (ISM) and are aligned with the magnetic field. Here we study the effect of grain alignment and grain motion on grain growth in molecular clouds (MCs). We first discuss the characteristic…
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…
Polarization arising from aligned dust grains presents a unique opportunity to study magnetic fields in the diffuse interstellar medium and molecular clouds. Polarization from circumstellar regions, accretion disks and comet atmospheres can…
Motivated by a recent study by Lazarian and Draine, which showed that a high degree of grain alignment of the paramagnetic dust is achievable if the rates of internal relaxation are controlled by the Barnett relaxation process, we undertake…
We generalize the magnetically enhanced radiative torque (MRAT) alignment theory for general astrophysical environments described by a dimensionless parameter $U/(n_{1}T_{2})$ with $U$ local radiation strength, $n_{1}=n_{\rm H}/(10{\rm…
We reveal a deep connection between alignment of dust grains by RAdiative torques (RATs) and MEchanical Torques (METs) and rotational disruption of grains introduced by Hoang et al. (2019). The disruption of grains happens if they have…
Paramagnetic alignment of thermally rotating oblate dust grains is studied analytically for finite ratios of grain to gas temperatures. For such ratios, the alignment of angular momentum J in respect to the grain axis of maximal inertia is…
Magnetic fields ($\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…
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…
Polarimetry is one of the most informative techniques of studying magnetic fields in molecular clouds. How reliable the interpretation of the polarization maps in terms of magnetic fields is the issue that the grain alignment theory…
Radiative Torques (RATs) or Mechanical Torques (METs) acting on irregular grains can induce the alignment of dust grains in respect to the alignment axis (AA), which can be either the direction of the magnetic field, or the direction of the…
Grain alignment by radiative torques (RATs) has been extensively studied for various environment conditions, including interstellar medium, dense molecular clouds, and accretion disks, thanks to significant progress in observational,…
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…
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,…
Thermal dust continuum polarimetry is a powerful indirect probe of magnetic field geometry in dense molecular clouds while at the same time providing information on the alignment of dust grains with the magnetic field. The leading theory of…
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…
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…