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Related papers: Grain Alignment, Polarization and Magnetic Fields

200 papers

Several of the current and next-generation cosmic microwave background (CMB) experiments have polarimetric capability, promising to add to the finesse of precision cosmology. One of the contaminating Galactic foregrounds is thermal emission…

Astrophysics · Physics 2009-11-11 P. G. Martin

We explore the induction of circular polarization (CP) of near-infrared light in star-forming regions using three-dimensional radiative transfer calculations. The simulations trace the change of Stokes parameters at each…

Astrophysics of Galaxies · Physics 2020-06-24 Hajime Fukushima , Hidenobu Yajima , Masayuki Umemura

Polarized extinction and emission from dust in the interstellar medium (ISM) are hard to interpret, as they have a complex dependence on dust optical properties, grain alignment and magnetic field orientation. This is particularly true in…

Astrophysics of Galaxies · Physics 2017-05-24 Lapo Fanciullo , Vincent Guillet , François Boulanger , Anthony Jones

Dust grains are important in various astrophysical processes and serve as indicators of interstellar medium structures, density, and mass. Understanding their physical properties and chemical composition is crucial in astrophysics. Dust…

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…

Astrophysics of Galaxies · Physics 2018-01-31 Thiem Hoang , Jungyeon Cho , A. Lazarian

Dust polarization, which comes from the alignment of aspherical grains to magnetic fields, has been widely employed to study the interstellar medium (ISM) dust properties. The wavelength dependence of the degree of optical polarization,…

Astrophysics of Galaxies · Physics 2024-11-15 Raphael Skalidis

Polarized dust continuum emission has been observed with ALMA in an increasing number of deeply embedded protostellar systems. It generally shows a sharp transition going from the protostellar envelope to the disk scale, with the…

Astrophysics of Galaxies · Physics 2021-08-04 Ka Ho Lam , Che-Yu Chen , Zhi-Yun Li , Haifeng Yang , Erin G. Cox , Leslie W. Looney , Ian Stephens

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

Cold, dense filaments, some appearing as infrared dark clouds, are the nurseries of stars. Tremendous progress in terms of temperature, density distribution and gas kinematics has been made in understanding the nature of these filaments.…

Astrophysics of Galaxies · Physics 2017-11-02 Thushara Pillai

The characterization of magnetic fields within molecular clouds is fundamental to understanding star formation processes. Accurately gauging the three-dimensional structure of these fields presents a challenge, as observational techniques…

Astrophysics of Galaxies · Physics 2024-11-18 Brandon Shane , Blakesley Burkhart , Laura Fissel , Susan E. Clark , Philip Mocz , Michael M. Foley

We compute polarization maps for molecular cloud cores modeled as magnetized singular isothermal toroids, under the assumption that the emitting dust grains are aspherical and aligned with the large-scale magnetic field. We show that,…

Astrophysics · Physics 2009-11-10 J. Goncalves , D. Galli , M. Walmsley

A detailed study of interstellar polarization efficiency toward molecular clouds is used to attempt discrimination between grain alignment mechanisms in dense regions of the ISM. Background field stars are used to probe polarization…

Astrophysics · Physics 2008-11-26 D. C. B. Whittet , J. H. Hough , A. Lazarian , Thiem Hoang

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…

Astrophysics · Physics 2009-11-13 Alex Lazarian , Thiem Hoang

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…

Astrophysics · Physics 2008-12-05 A. Lazarian

The configuration and evolution of the magnetic field in star-forming cores are investigated in order to directly compare simulations and observations. We prepare four different initial clouds having different magnetic field strengths and…

Solar and Stellar Astrophysics · Physics 2015-06-11 Akimasa Kataoka , Masahiro N. Machida , Kohji Tomisaka

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…

Astrophysics of Galaxies · Physics 2024-03-01 Enrique Lopez-Rodriguez , Le Ngoc Tram

Polarized emission from interstellar dust grains is commonly used to infer information about the underlying magnetic field from the diffuse interstellar medium to molecular cloud cores. Therefore, the ability to accurately determine…

Solar and Stellar Astrophysics · Physics 2026-02-19 Marco Leon Scheiter , Sebastian Wolf

Irregular dust grains are subject to radiative torques when irradiated by interstellar starlight. It is shown how these radiative torques may be calculated using the discrete dipole approximation. Calculations are carried out for one…

Astrophysics · Physics 2009-10-28 B. T. Draine , Joseph C. Weingartner

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

This paper provides testable predictions about starlight polarizations to constrain the geometry of the Galactic magnetic field, in particular the nature of the poloidal component. Galactic dynamo simulations and Galactic dust distributions…

Astrophysics of Galaxies · Physics 2012-02-07 Michael D. Pavel