相关论文: Tracing Magnetic Fields with Aligned Grains
Most astrophysical systems, e.g. stellar winds, the diffuse interstellar medium, molecular clouds, are magnetized with magnetic fields that influence almost all of their properties. One of the most informative techniques of magnetic field…
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…
One of the most informative techniques of studying magnetic fields in molecular clouds is based on the use of starlight polarization and polarized emission arising from aligned dust. How reliable the interpretation of the polarization maps…
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…
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,…
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…
Aligned non-spherical dust particles polarize starlight passing through the dust cloud. They also emit polarized far infrared and sub-mm radiation. Substantial progress in understanding of grain alignment theory makes the interpretation of…
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…
Magnetic fields are ubiquitous in the universe and are thought to play an important role in various astrophysical processes. Polarization of thermal dust emission from dust grains aligned with the magnetic field is widely used to measure…
Grain alignment is a notoriously difficult problem, that is extremely rich in underlying physics. The long history of attempts theoretical handling of the problem resulted in rather sceptical approach to the theory on the part of some…
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…
The alignment of interstellar dust grains with magnetic fields provides a key method for measuring the strength and morphology of the fields. In turn, this provides a means to study the role of magnetic fields from diffuse gas to dense…
Polarized microwave emission from dust is an important foreground that may contaminate polarized CMB studies unless carefully accounted for. Modeling of polarization from dust requires a quantitative understanding of grain alignment. I…
Aligned grains present a foreground for cosmic microwave emission studies. We review basic physical processes involved in grain alignment and discuss the niches for different alignment mechanisms. We show that mechanisms which were favored…
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…
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…
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…
Observational studies of magnetic fields are vital as magnetic fields play a crucial role in various astrophysical processes, including star formation, accretion of matter, transport processes (e.g., transport of heat), and cosmic rays. We…
The optical and magnetic properties of dust grains are reviewed, as they relate to the problem of interstellar grain alignment. Grain geometry plays an important role in determining the optical properties, and scattering and absorption of…
Polarization carries information about the magnetic fields in interstellar clouds. The observations of polarized dust emission are used to study the role of magnetic fields in the evolution of molecular clouds and the initial phases of…