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Related papers: Grain Alignment in Molecular Clouds

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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…

In order to interpret observations influenced by dust and to perform detailed modeling of the observable characteristics of dust-producing or dust-containing objects, knowledge of the micro-physical properties of relevant dust species are…

Astrophysics of Galaxies · Physics 2012-01-20 Anja C. Andersen

(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…

Astrophysics · Physics 2009-11-10 D. S. Wiebe , W. D. Watson

$\textit{Aims.}$ We present a case study to demonstrate the potential of multi-wavelength polarization measurements. The aim is to investigate the effects that dichroic polarization and thermal re-emission have on tracing the magnetic field…

Solar and Stellar Astrophysics · Physics 2015-06-19 S. Reissl , S. Wolf , D. Seifried

The polarization observed for stars background to dark clouds (Bok Globules) is often used as diagnostic to study the ongoing star formation processes in these clouds. Such polarization in the optical have been reported for eight nearby…

Astrophysics · Physics 2009-09-15 A. K. Sen , T. Mukai , R. Gupta , H. S. Das

Aligned interstellar grains produce polarized extinction (observed at wavelengths from the far-ultraviolet to the mid-infrared), and polarized thermal emission (observed at far-infrared and submm wavelengths). The grains must be quite…

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

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 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…

Astrophysics of Galaxies · Physics 2022-06-01 Sadhana Singh , Jeewan C. Pandey , Thiem Hoang

Nine lectures reviewing the astrophysics of dust in interstellar clouds. Topics include: (1) Summary of observational evidence concerning interstellar dust: broadband extinction, scattering of starlight, polarization of starlight,…

Astrophysics · Physics 2007-05-23 B. T. Draine

We develop a theory for filamentary molecular clouds including the effects of ordered magnetic fields, and external pressure. We first derive a form of the virial equation appropriate for filamentary clouds. By comparing with observational…

Astrophysics · Physics 2007-05-23 Jason D. Fiege , Ralph E. Pudritz

Dust polarization depends on the physical and mechanical properties of dust, as well as the properties of local environments. To understand how dust polarization varies with grain mechanical properties and the local environment, in this…

Astrophysics of Galaxies · Physics 2020-06-17 Hyeseung Lee , Thiem Hoang , Ngan Le , Jungyeon Cho

By comparing cumulative linear mass profiles of 12 Gould Belt molecular clouds within 500 pc, we study how the linear mass distributions of molecular clouds vary with the angles between the molecular cloud long axes and the directions of…

Astrophysics of Galaxies · Physics 2019-06-25 Chi Yan Law , Hua Bai Li , Pokin Leung

ALMA observations revealed recently polarised radiation of several protoplanetary disks in the (sub-)millimetre wavelength range. Besides self-scattering of large particles, thermal emission by elongated grains is a potential source for the…

Earth and Planetary Astrophysics · Physics 2019-07-10 Florian Kirchschlager , Gesa H. -M. Bertrang , Mario Flock

The properties of polarization in scattered light by aligned ellipsoidal grains are investigated with the Fredholm integral equation method (FIM) and the T-matrix method (Tmat), and the results are applied to the observed circular…

Astrophysics of Galaxies · Physics 2010-01-15 Masafumi Matsumura , Pierre Bastien

We discuss a new technique of studying magnetic fields in diffuse astrophysical media, e.g. interstellar and intergalactic gas/plasma. This technique is based on the angular momentum alignment of atoms and ions in their ground or metastable…

Astrophysics · Physics 2008-06-24 Huirong Yan , A. Lazarian

We compiled the polarimetric data for a sample of lines of sight with known abundances of Mg, Si, and Fe. We correlated the degree of interstellar polarization $P$ and polarization efficiency (the ratio of $P$ to the colour excess $E(B-V)$…

Astrophysics of Galaxies · Physics 2015-06-04 N. V. Voshchinnikov , Th. Henning , M. S. Prokopjeva , H. K. Das

Our current understanding of interstellar dust is summarized at an introductory level. Submicron-sized interstellar dust grains absorb and scatter light, and reradiate the absorbed energy in the infrared. The grain population spans a range…

Astrophysics · Physics 2009-10-31 B. T. Draine

We present a statistical analysis of the interstellar medium (ISM) polarization from the largest compilation available of starlight data, which comprises ~ 5500 stars. The measured correlation between the mean polarization degree and…

Astrophysics · Physics 2014-10-13 Pablo Fosalba , Alex Lazarian , Simon Prunet , Jan A. Tauber

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

Disk polarization in (sub)millimeter dust continuum is a rapidly growing field in the ALMA era. It opens up the exciting possibility of detecting and characterizing magnetic fields and grain growth in disks around young stellar objects.…

Solar and Stellar Astrophysics · Physics 2018-12-12 Haifeng Yang , Zhi-Yun Li , Ian W. Stephens , Akimasa Kataoka , Leslie Looney