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We propose a new technique for weak gravitational lensing in the radio band making use of polarization information. Since the orientation of a galaxy's polarized emission is both unaffected by lensing and is related to the galaxy's…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Michael L. Brown , Richard A. Battye

Requirements for magnetic coupling and accretion in the active layer of a protostellar disk are re-examined, and some implications for thermal emission from the layer are discussed. The ionization and electrical conductivity are calculated…

Solar and Stellar Astrophysics · Physics 2009-08-05 Xue-Ning Bai , Jeremy Goodman

This article combines new CCD polarimetric data with previous information about protostellar objects in a search for correlations involving the interstellar magnetic field. Specifically, we carried out an optical polarimetric study of a…

Solar and Stellar Astrophysics · Physics 2011-11-24 Cristiane G. Targon , Claudia V. Rodrigues , Adriano H. Cerqueira , Gabriel R. Hickel

We study the alignment and rotational disruption of dust grains at the centre of our Galaxy using polarized thermal dust emission observed by SOFIA/HAWC+ and JCMT/SCUPOL at 53, 216, and 850 $\mu$m. We analyzed the relationship between the…

Astrophysics of Galaxies · Physics 2023-05-01 M. S. Akshaya , Thiem Hoang

We present a statistical analysis of Galactic interstellar polarization from the largest compilation available of starlight data. The data comprises ~ 9300 stars of which we have selected ~ 5500 for our analysis. We find a nearly linear…

Astrophysics · Physics 2009-11-06 Pablo Fosalba , Alex Lazarian , Simon Prunet , Jan A. Tauber

The millimeter-wave polarization of the protoplanetary disk around HL Tau has been interpreted as the emission from elongated dust grains aligned with the magnetic field in the disk. However, the self-scattering of thermal dust emission may…

Earth and Planetary Astrophysics · Physics 2016-03-23 Akimasa Kataoka , Takayuki Muto , Munetake Momose , Takashi Tsukagoshi , Cornelis P Dullemond

It is generally assumed that magnetic fields play an important role in the formation and evolution of protoplanetary disks. One way of observationally constraining magnetic fields is to measure polarized emission and absorption produced by…

Solar and Stellar Astrophysics · Physics 2020-03-04 Stefan Heese , Sebastian Wolf

During the last decade, the FORS1 instrument of the ESO Very Large Telescope has been used to obtain low resolution circular polarized spectra for about 500 stars, with the aim of measuring their mean longitudinal magnetic fields. Magnetic…

Solar and Stellar Astrophysics · Physics 2015-05-30 S. Bagnulo , J. D. Landstreet , L. Fossati , O. Kochukhov

Within four nearby (d < 160 pc) molecular clouds, we statistically evaluate the structure of the interstellar magnetic field, projected on the plane of the sky and integrated along the line of sight, as inferred from the polarized thermal…

We present a method for parametric modelling of the physical components of the Galaxy's magnetised interstellar medium, simulating the observables, and mapping out the likelihood space using a Markov Chain Monte-Carlo analysis. We then…

Astrophysics of Galaxies · Physics 2010-01-29 T. R. Jaffe , J. P. Leahy , A. J. Banday , S. M. Leach , S. R. Lowe , A. Wilkinson

Interstellar dust grains are non-spherical and, in some environments, partially aligned along the direction of the interstellar magnetic field. Numerous alignment theories have been proposed, all of which examine the grain rotational…

Astrophysics of Galaxies · Physics 2021-03-15 Joseph C. Weingartner , Erald Kolasi , Cameron Woods

The presence of ferromagnetic or ferrimagnetic nanoparticles in the interstellar medium would give rise to magnetic dipole radiation at microwave and submm frequencies. Such grains may account for the strong mm-wavelength emission observed…

Astrophysics of Galaxies · Physics 2015-06-05 B. T. Draine , Brandon Hensley

We study the efficiency of grain alignment by radiative torques (RATs) for an ensemble of irregular grains. The grains are modeled as ensembles of oblate and prolate spheroids, deformed as Gaussian random ellipsoids, and their scattering…

Astrophysics of Galaxies · Physics 2021-06-02 Joonas Herranen , A. Lazarian , Thiem Hoang

We investigate the efficiency of interstellar polarization $p_\lambda/A_\lambda$ where $p_\lambda$ is the fractional linear polarization and $A_\lambda$ is extinction, in 16 lines of sight as a function of wavelength $\lambda$. We have used…

Astrophysics of Galaxies · Physics 2015-05-27 Masafumi Matsumura , Youko Kameura , Koji S. Kawabata , Hiroshi Akitaya , Mizuki Isogai , Munezo Seki

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

This paper provides a quantitative account of a recently introduced mechanism of mechanical alignment of suprathermally rotating grains. These rapidly rotating grains are essentially not susceptible to random torques arising from gas-grain…

Astrophysics · Physics 2009-10-28 Alex Lazarian , Michael Efroimsky

Low-energy spin-polarized electrons (SPEs) are thought to cause symmetry breaking and could explain the origin of homochirality of prebiotic molecules such as amino acids and sugars. Here we study the effect of cosmic rays (CRs) on the…

Astrophysics of Galaxies · Physics 2025-04-22 Thiem Hoang

Earlier studies of grain alignment dealt mostly with interstellar grains that have strong internal relaxation of energy which aligns grain axis of maximum moment of inertia with respect to grain's angular momentum. In this paper, we study…

Astrophysics · Physics 2010-01-15 Thiem Hoang , Alex Lazarian

The mechanisms causing millimeter-wave polarization in protoplanetary disks are under debate. To disentangle the polarization mechanisms, we observe the protoplanetary disk around HL Tau at 3.1 mm with the Atacama Large…

Earth and Planetary Astrophysics · Physics 2017-07-26 Akimasa Kataoka , Takashi Tsukagoshi , Adriana Pohl , Takayuki Muto , Hiroshi Nagai , Ian W. Stephens , Kohji Tomisaka , Munetake Momose

In this paper, we present a triaxial alignment magnetometer based on free-spin precession deployed in the geomagnetic range. Existing vector measurement methods often require complex optical setups, heating structures, and laser modulation.…

Atomic Physics · Physics 2025-02-18 Ge Jin , Tao Shi , Sheng Zou