Related papers: Grain alignment and disruption by radiative torque…
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…
An increasing number of young circumstellar disks show strikingly ordered (sub)millimeter polarization orientations along the minor axis, which is strong evidence for polarization due to scattering by ~0.1 mm sized grains. To test this…
We have investigated the grain alignment and dust properties towards the direction of the cluster NGC 2345 using the multi-band optical polarimetric observations. For the majority of the stars, the observed polarization is found to be due…
Recent observational progress has challenged the dust grain-alignment theories used to explain the polarized dust emission routinely observed in star-forming cores. In an effort to improve our understanding of the dust grain alignment…
Magnetic fields (B-fields) in galaxies have recently been traced using far-infrared and sub-mm polarimetric observations with SOFIA, JCMT, and ALMA. The main assumption is that dust grains are magnetically aligned with the local B-field in…
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…
Interstellar dust grains can be spun up by radiative torques, and the resulting centrifugal force may be strong enough to disrupt large dust grains. We examine the effect of this rotational disruption on the evolution of grain size…
We present a novel method to measure the strength of interstellar magnetic fields based on ultraviolet (UV) polarization of starlight, which is in part produced by weakly aligned, small interstellar grains. We begin with calculating degrees…
High angular resolution observations of Class 0 protostars have produced detailed maps of the polarized dust emission in the envelopes of these young embedded objects. Interestingly, the improved sensitivity brought by ALMA has revealed…
A systematic torque from anisotropic radiation can rapidly spin up irregular grains to the point of breakup. We apply the standard theory of rotational disruption from radiative torques to solar system grains, finding that grains with radii…
Polarization at millimeter wavelengths provides a powerful diagnostic of dust grain properties in protoplanetary disks. Standard models based on solid spherical grains often struggle to reproduce the observed polarization fractions and…
The origin of polarized emission from protoplanetary disks is uncertain. Three mechanisms have been proposed for such polarized emission: grain alignment with magnetic fields, grain alignment with radiation gradients, and self-scattering of…
Dust polarization at (sub)millimeter wavelengths has been observed for many protoplanetary disks. Theoretically, multiple origins potentially contribute to the polarized emission but it is still uncertain what mechanism is dominant in disk…
The quantization of energy levels in very nanoparticles suppresses dissipative processes that convert grain rotational kinetic energy into heat. For grains small enough to have GHz rotation rates, the suppression of dissipation can be…
Dust in the diffuse interstellar medium remains incompletely understood with regard to the structure, composition, size distribution, and alignment properties of the grains. Joint observations of reddening, starlight polarisation spectra,…
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. One of the easiest ways to determine the magnetic field…
(abridged) The polarized thermal radiation at far infrared and submillimeter wavelengths from dust grains in interstellar clouds with irregular magnetic fields is simulated. We show that the polarization properties of quiescent clouds and…
Recently discovered scattered light from molecular cloud cores in the wavelength range 3-5 {\mu}m (called "coreshine") seems to indicate the presence of grains with sizes above 0.5 {\mu}m. We aim to analyze 3.6 and 4.5 {\mu}m coreshine from…
We investigate the condition for the formation of micron-sized grains in dense cores of molecular clouds. This is motivated by the detection of the mid-infrared emission from deep inside a number of dense cores, the so-called `coreshine,'…
We attempt to get a physical insight into grain alignment processes by studying basic properties of radiative torques (RATs). For this purpose we consider a simple toy model of a helical grain that reproduces well the basic features of…