相关论文: Gold alignment & internal dissipation
We show that grains can be efficiently aligned by interacting with a subsonic gaseous flow. The alignment arises from grains having irregularities that scatter atoms with different efficiency in the right and left directions. The grains…
We study the physical processes inducing the alignment of the grain axis of maximum inertia moment with the angular momentum (${\bf J}$, i.e., internal alignment) and of ${\bf J}$ with the magnetic field (i.e., external alignment) of very…
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…
We present extensive calculations on the efficiency of grain alignment by the Davis-Greenstein mechanism. We model the grains as oblate spheroids with arbitrary axis ratios. Our description of the grain dynamics includes (i) magnetic…
We present an exact formulation of the physics of Barnett relaxation. Our formulation is based on a realistic kinetic model of the relaxation mechanism which includes the alignment of the grain angular momentum in body coordinates by…
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…
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…
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…
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…
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.…
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…
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…
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…
We show that the energy-level splitting arising from grain rotation ensures that paramagnetic dissipation acts at its maximum rate, i.e., the conditions for paramagnetic resonance are automatically fulfilled. We refer to this process as…
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…
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 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…
Interstellar polarization in the optical/infrared has long been known to be due to asymmetrical dust grains aligned with the magnetic field and can potentially provide a resource effective way to probe both the topology and strength of the…
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…
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…