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Related papers: Grain Alignment in Starless Cores

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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

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

We extend previous theoretical works to gain a better understanding of the origin of observed polarisation degree spectra of molecular clouds, which show a so-called V-shape, i.e. a pronounced minimum around 350~$\mu$m. For this purpose, we…

Astrophysics of Galaxies · Physics 2025-09-03 Daniel Seifried , Stefanie Walch , Thorsten Balduin

Dust plays a central role in the unification theory of active galactic nuclei (AGNs). However, little is known about the nature (e.g., size, composition) of the dust which forms a torus around the AGN. In this Letter we report a systematic…

Astrophysics of Galaxies · Physics 2015-06-22 Jianwei Lyu , Lei Hao , Aigen Li

Progress in understanding star formation requires detailed observational constraints on the initial conditions, i.e. dense clumps and cores in giant molecular clouds that are on the verge of gravitational instability. Such structures have…

Solar and Stellar Astrophysics · Physics 2016-09-23 Wanggi Lim , Jonathan C. Tan

We present results of our study on eight dense cores, previously classified as starless, using infrared (3-160 {\micron}) imaging observations with \textit{AKARI} telescope and molecular line (HCN and N$_2$H$^+$) mapping observations with…

Astrophysics of Galaxies · Physics 2016-06-22 Gwanjeong Kim , Chang Won Lee , Maheswar Gopinathan , Woong-Seob Jeong , Mi-Ryang Kim

We interpret the relation between the polarizing efficiency $P_{\max}/E(B-V)$ and the wavelength of the maximum polarization $\lambda_{\max}$ observed for 17 objects (including 243 stars) separated into two groups: "dark clouds" and "open…

Astrophysics of Galaxies · Physics 2016-10-12 N. V. Voshchinnikov , V. B. Il'in , H. K. Das

Disk polarization at (sub)millimeter wavelengths is being revolutionized by ALMA observationally, but its origin remains uncertain. Dust scattering was recently recognized as a potential contributor to polarization, although its basic…

Solar and Stellar Astrophysics · Physics 2017-11-08 Haifeng Yang , Zhi-Yun Li , Leslie W. Looney , Josep M. Girart , Ian W. Stephens

Dust polarization at (sub)millimeter wavelengths has been observed for many protoplanetary disks. Theoretically, multiple origins potentially contribute to the polarized emission but it is still uncertain what mechanism is dominant in disk…

Earth and Planetary Astrophysics · Physics 2021-03-03 Tomohiro Mori , Akimasa Kataoka

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

Polarimetry in the far-infrared and submillimeter has been valuable in tracing magnetic fields in bright Galactic Clouds. We discuss the techniques we have developed and trends we have found in polarization vs column density, and vs…

Astrophysics · Physics 2015-06-24 Roger Hildebrand

We present detailed models of irradiated T Tauri disks including dust grain growth with power-law size distributions. The models assume complete mixing between dust and gas and solve for the vertical disk structure…

Astrophysics · Physics 2009-11-06 Paola D'Alessio , Nuria Calvet , Lee Hartmann

(Aims) In this work, we predict the far-infrared polarisation signal emitted by non-spherical dust grains in nearby galaxies. We determine the angular resolution and sensitivity required to study the magnetic field configuration in these…

The dust properties inferred from the analysis of Planck observations in total and polarized emission challenge current dust models. We propose new dust models compatible with polarized and unpolarized data in extinction and emission for…

Astrophysics of Galaxies · Physics 2018-02-21 V. Guillet , L. Fanciullo , L. Verstraete , F. Boulanger , A. P. Jones , M. -A. Miville-Deschênes , N. Ysard , F. Levrier , M. Alves

The size of dust grains, $a$, is key to the physical and chemical processes in circumstellar disks, but observational constraints of grain size remain challenging. (Sub)millimeter continuum observations often show a percent-level…

The polarized dust emission observed in Class 0 protostellar cores at high angular resolution with ALMA has raised several concerns about the grain alignment conditions in these regions. We aim to study the role of the radiation field on…

We present a comparison of the gas and dust properties of the dense interstellar matter in six nearby star-forming regions (d<500 pc): rho Oph, Cha I, R CrA, IC 348, NGC 1333, and Orion. We measure from Chandra and XMM-Newton observations…

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

Most astrophysical systems, e.g. stellar winds, the diffuse interstellar medium, molecular clouds, are magnetized with magnetic fields that influence almost all of their properties. One of the most informative techniques of magnetic field…

Astrophysics · Physics 2009-11-07 A. Lazarian

In this paper we present the results of a high resolution (5") CARMA and SZA survey of the 3mm continuum emission from 11 of the brightest (at 1.1mm) starless cores in the Perseus molecular cloud. We detect 2 of the 11 cores, both of which…

Astrophysics of Galaxies · Physics 2015-05-19 Scott Schnee , Melissa Enoch , Doug Johnstone , Thomas Culverhouse , Erik Leitch , Daniel P. Marrone , Anneila Sargent