English
Related papers

Related papers: GRAIN ALIGNMENT IN THE TAURUS DARK CLOUD

200 papers

Dust polarization induced by aligned grains is widely used to study magnetic fields in various environments, including star-forming regions. However, the question of to what optical depth grain alignment still exists in a dense molecular…

Astrophysics of Galaxies · Physics 2021-03-03 Thiem Hoang , Le Ngoc Tram , Hyeseung Lee , Pham Ngoc Diep , Nguyen Bich Ngoc

Polarized (sub)millimeter emission from dust grains in circumstellar disks was initially thought to be due to grains aligned with the magnetic field. However, higher resolution multi-wavelength observations along with improved models found…

Magnetic fields are thought to influence the formation and evolution of circumstellar envelopes around evolved stars. Thermal dust polarization from aligned grains is a promising tool for probing magnetic fields and dust properties in these…

Solar and Stellar Astrophysics · Physics 2024-12-05 Bao Truong , Thiem Hoang , Nguyen Chau Giang , Pham Ngoc Diep , Dieu D. Nguyen , Nguyen Bich Ngoc

An optically and geometrically thick torus obscures the central engine of Active Galactic Nuclei (AGN) from some lines of sight. From a magnetohydrodynamical framework, the torus can be considered to be a particular region of clouds…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-21 E. Lopez-Rodriguez , C. Packham , S. Young , M. Elitzur , N. A. Levenson , R. E. Mason , C. Ramos Almeida , A. Alonso-Herrero , T. J. Jones , E. Perlman

Few normal galaxies have been probed using near-infrared polarimetry, even though it reveals magnetic fields in the cool interstellar medium better than either optical or radio polarimetry. Deep H-band (1.6um) linear imaging polarimetry…

Astrophysics of Galaxies · Physics 2015-06-12 Dan P. Clemens , M. D. Pavel , L. R. Cashman

Dust polarization induced by aligned non-spherical grains acts as an important tool to trace the magnetic field (B-field) morphologies and strengths in molecular clouds and constrain grain properties and their alignment mechanisms. The…

Astrophysics of Galaxies · Physics 2026-03-03 Saikhom Pravash , Thiem Hoang , Archana Soam , Qi-Lao Gu , Tie Liu , Pham Ngoc Diep , Le Ngoc Tram , Nguyen Bich Ngoc

The alignment of dust grains with the ambient magnetic field produces polarization of starlight as well as thermal dust emission. Using the archival SOFIA/HAWC+ polarimetric data observed toward $\rho$ Ophiuchus (Oph) A cloud hosted by a B…

Astrophysics of Galaxies · Physics 2021-01-25 Le Ngoc Tram , Thiem Hoang , Hyeseung Lee , Fabio Santos , Archana Soam , Pierre Lesaffre , Antoine Gusdorf , William Reach

Context. Planck observations demonstrated that the grain alignment efficiency is almost constant in the diffuse ISM. Aims. We test if the Radiative Torque (RAT) theory is compatible with observational constraints on grain alignment.…

Instrumentation and Methods for Astrophysics · Physics 2020-08-26 Stefan Reissl , Vincent Guillet , Robert Brauer , François Levrier , François Boulanger , Ralf S. Klessen

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…

Astrophysics · Physics 2016-08-30 A. Lazarian , J. Cho

The motion of diamagnetic dust particles in interstellar magnetic fields is studied numerically with several different sets of parameters. Two types of behavior are observed, depending on the value of the critical number $R$, which is a…

Astrophysics of Galaxies · Physics 2018-02-21 Renaud Papoular

Maps of estimated dust column density in molecular clouds are usually assumed to reliably trace the total gas column density structure. In this work we present results showing a clear discrepancy between the dust and the gas distribution in…

Dust polarization observations at optical wavelengths help to understand the dust grain properties and trace the plane-of-the-sky component of the magnetic field. In this study, we make use of the $I$-band polarization data acquired from…

Astrophysics of Galaxies · Physics 2022-08-09 N. Bijas , Chakali Eswaraiah , Jia-Wei Wang , Jessy Jose , Wen-Ping Chen , Di Li , Shih-Ping Lai , D. K. Ojha

We present optical and near-infrared stellar polarization observations toward the dark filamentary clouds associated with IC5146. The data allow us to investigate the dust properties (this paper) and the magnetic field structure (Paper II).…

Astrophysics of Galaxies · Physics 2017-11-15 Jia-Wei Wang , Shih-Ping Lai , C. Eswaraiah , Dan P. Clemens , Wen-Ping Chen , A. K. Pandey

We observed the L1506 filament, which is located in the Taurus molecular complex, with the Herschel PACS and SPIRE instruments. Our aim is to prove the variation in grain properties along the entire length of the filament. In particular, we…

Polarization of starlight and thermal dust emission due to aligned non-spherical grains helps us to trace magnetic field (B-field) morphology in molecular clouds and to study grain alignment mechanisms. In this work, we study grain…

Astrophysics of Galaxies · Physics 2025-01-22 Saikhom Pravash , Archana Soam , Pham Ngoc Diep , Thiem Hoang , Nguyen Bich Ngoc , Le Ngoc Tram

Magnetic fields play essential roles in protoplanetary disks. Magnetic fields in the disk atmosphere are of particular interest, as they are connected to the wind-launching mechanism. In this work, we study the polarization of the light…

Earth and Planetary Astrophysics · Physics 2022-08-24 Haifeng Yang , Zhi-Yun Li

Interstellar dust grains are often aligned. If the grain alignment direction varies along the line of sight, the thermal emission becomes circularly-polarized. In the diffuse interstellar medium, the circular polarization at far-infrared…

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

It is well known that the polarized continuum emission from magnetically aligned dust grains is determined to a large extent by local magnetic field structure. However, the observed significant anticorrelation between polarization fraction…

Astrophysics of Galaxies · Physics 2019-10-02 Patrick K. King , Che-Yu Chen , Laura M. Fissel , Zhi-Yun Li

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

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,…

Astrophysics · Physics 2007-05-23 Lazarian A