English
Related papers

Related papers: On the efficiency of grain alignment in dark cloud…

200 papers

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

Polarized dust emission is a key tracer in the study of interstellar medium and of star formation. The observed polarization, however, is a product of magnetic field structure, dust grain properties and grain alignment efficiency, as well…

We present synthetic dust polarisation maps of 3D magneto-hydrodynamical simulations of molecular clouds before the onset of stellar feedback. The clouds are modelled within the SILCC-Zoom project and are embedded in their galactic…

Astrophysics of Galaxies · Physics 2018-10-31 D. Seifried , S. Walch , S. Reissl , J. C. Ibáñez-Mejía

We present 870 $\mu$m ALMA polarization observation toward the Class I\hspace{-.1em}I protoplanetary disk around AS 209, which has concentric, multiple gaps and rings. We successfully detect the polarized emission and find that the…

Earth and Planetary Astrophysics · Physics 2019-09-25 Tomohiro Mori , Akimasa Kataoka , Satoshi Ohashi , Munetake Momose , Takayuki Muto , Hiroshi Nagai , Takashi Tsukagoshi

We develop a comprehensive quantitative description of the cross-section mechanism discovered several years ago by Lazarian. This is one of the processes that determine grain orientation in clouds of suprathermal cosmic dust. The…

Astrophysics · Physics 2009-11-07 Michael Efroimsky

We use polarimetric observations of two stars (HD29647, HD283809) in the general direction of TMC-1 in the Taurus Dark Cloud to investigate grain properties and cloud structure in this region. We show the data to be consistent with a simple…

Astrophysics · Physics 2009-10-30 D. W. Messinger , D. C. B. Whittet , W. G. Roberge

We use the PPMAP (Point Process MAPping) algorithm to re-analyse the \textit{Herschel} and SCUBA-2 observations of the L1688 and L1689 sub-regions of the Ophiuchus molecular cloud. PPMAP delivers maps with high resolution (here $14''$,…

Astrophysics of Galaxies · Physics 2021-05-12 A. D. P. Howard , A. P. Whitworth , M. J. Griffin , K. A. Marsh , M. W. L. Smith

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

The radiative torque (RAT) mechanism is the most promising way of explaining observed polarization arising from aligned grains. We explore the efficiency of the grain alignment by an anisotropic radiation flow for an extensive ensemble of…

Astrophysics of Galaxies · Physics 2019-06-26 Joonas Herranen , Alex Lazarian , Thiem Hoang

Dust grains grow their sizes in the interstellar clouds (especially in molecular clouds) by accretion and coagulation. Here we model and test these processes by examining the consistency with the observed variation of the extinction curves…

Astrophysics of Galaxies · Physics 2015-06-17 Hiroyuki Hirashita , Nikolai V. Voshchinnikov

We report on polarimetric maps made with HAWC+/SOFIA toward Rho Oph A, the densest portion of the Rho Ophiuchi molecular complex. We employed HAWC+ bands C (89 $\mu$m) and D (154 $\mu$m). The slope of the polarization spectrum was…

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

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

We have analyzed the properties of dust in the high galactic latitude translucent cloud Lynds 1780 using ISOPHOT maps at 100 and 200 micrometers and raster scans at 60, 80, 100, 120, 150 and 200 micrometers. In far-infrared (FIR) emission,…

Astrophysics · Physics 2009-11-11 M. Ridderstad , M. Juvela , K. Lehtinen , D. Lemke , T. Liljestrom

Telescopes are now able to resolve dust polarization across circumstellar disks at multiple wavelengths, allowing the study of the polarization spectrum. Most disks show clear evidence of dust scattering through their unidirectional…

Solar and Stellar Astrophysics · Physics 2022-04-27 Zhe-Yu Daniel Lin , Zhi-Yun Li , Haifeng Yang , Ian Stephens , Leslie Looney , Rachel Harrison , Manuel Fernández-López

(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

Several mechanisms have been proposed to explain the alignment of grains with the interstellar magnetic field, including paramagnetic dissipation, radiative torques, and supersonic gas-grain streaming. These must compete with disaligning…

Astrophysics · Physics 2008-11-26 Joseph C. Weingartner

Polarization of starlight induced by dust grains aligned with the magnetic field (hereafter B-field) is widely used to measure the two-dimensional B-fields projected onto the plane-of-sky. Here, we introduce a new method to infer…

Astrophysics of Galaxies · Physics 2025-02-04 Bao Truong , Thiem Hoang

Motivated by a recent study by Lazarian and Draine, which showed that a high degree of grain alignment of the paramagnetic dust is achievable if the rates of internal relaxation are controlled by the Barnett relaxation process, we undertake…

Astrophysics · Physics 2009-10-31 A. Lazarian , M. Efroimsky

We have computed the size distribution of silicate grains in the outer radiative region of the envelope of a protoplanet evolving according to the scenario of Pollack et al. (1996). Our computation includes grain growth due to Brownian…

Astrophysics · Physics 2009-11-13 Naor Movshovitz , Morris Podolak
‹ Prev 1 3 4 5 6 7 10 Next ›