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Related papers: Grain Alignment in Starless Cores

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Recent high-resolution observations at millimeter (mm) and sub-mm reveal a diverse spatial distribution for sub-pc scale dense cores within star-forming regions, ranging from clustered to aligned arrangements. To address the increasing…

Astrophysics of Galaxies · Physics 2024-12-04 Wei-An Chen , Ya-Wen Tang , Seamus D. Clarke

We present polarisation spectra of seven stars in the lines-of-sight towards the Sco OB1 association. Our spectra were obtained within the framework of the Large Interstellar Polarization Survey carried out with the FORS instrument of the…

Astrophysics of Galaxies · Physics 2017-12-20 R. Siebenmorgen , N. V. Voshchinnikov , S. Bagnulo , Cox N. L. J.

In a companion paper, Maiolino et al. (2000) presented various observational evidences for "anomalous" dust properties in the circumnuclear region of AGNs and, in particular, the reduced E(B-V)/N_H and Av/N_H ratios, the absence of the…

Astrophysics · Physics 2009-10-31 R. Maiolino , A. Marconi , E. Oliva

In the framework of the silicate core-carbonaceous organic mantle interstellar dust model, the bulk of the visual/near-IR extinction and the entire polarization are from nonspherical and aligned core-mantle grains. The 3.4 micron C-H and…

Astrophysics · Physics 2009-11-07 Aigen Li , J. Mayo Greenberg

We have studied the opacity of dust grains at submillimeter wavelengths by estimating the optical depth from imaging at 160, 250, 350, and 500 um from the Herschel Gould Belt Survey and comparing this to a column density obtained from the…

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

Observations of interstellar dust are often used as a proxy for total gas column density $N_\mathrm{H}$. By comparing $\textit{Planck}$ thermal dust data (Release 1.2) and new dust reddening maps from Pan-STARRS 1 and 2MASS (Green et al.…

Despite the pervasive nature of interstellar dust and its impact on nearly all observations, most dust corrections employ line-of-sight averages over large angular scales. This neglects real variations on small angular and distance scales…

Astrophysics of Galaxies · Physics 2025-09-05 Jordan A. Bartlett , Henry A. Kobulnicky

Context: Observations of scattered light in the 1-5 $\mu$m range have revealed dust grains in molecular cores with sizes larger than commonly inferred for the diffuse interstellar medium. It is currently unclear whether these grains are…

Astrophysics of Galaxies · Physics 2014-09-05 M. Andersen , W-F. Thi , J. Steinacker , N. Tothill

High angular resolution observations of Class 0 protostars have produced detailed maps of the polarized dust emission in the envelopes of these young embedded objects. Interestingly, the improved sensitivity brought by ALMA has revealed…

Astrophysics of Galaxies · Physics 2023-03-29 Valentin J. M. Le Gouellec , Anaëlle J. Maury , Charles L. H. Hull

We argue that impact velocities between dust grains with sizes less than $\sim 0.1$ $\mu m$ in molecular cloud cores are dominated by drift arising from ambipolar diffusion. This effect is due to the size dependence of the dust coupling to…

Astrophysics of Galaxies · Physics 2020-09-30 Kedron Silsbee , Alexei Ivlev , Paola Caselli , Olli Sipila , Bo Zhao

I explore models of the dust-scattered component of the Cosmic Ultraviolet Background (CUVB) at the North Galactic Pole (NGP) in order to develop a framework for calculating the dust-scattered light as a function of the optical depths. As…

Instrumentation and Methods for Astrophysics · Physics 2025-07-08 Jayant Murthy

Recently discovered scattered light at 3-5 $\mu$m from low-mass cores (so-called "coreshine") reveals the presence of grains around 1 $\mu$m, which is larger than the grains found in the low-density interstellar medium. But only about half…

Astrophysics of Galaxies · Physics 2015-06-18 J. Steinacker , M. Andersen , W. -F. Thi , A. Bacmann

Dust plays a central role in the unification theory of active galactic nuclei (AGNs). Whether the dust that forms the torus around an AGN is tenth-$\mu$m-sized like interstellar grains or much larger has a profound impact on correcting for…

Astrophysics of Galaxies · Physics 2017-05-10 Z. Z. Shao , B. W. Jiang , Aigen Li

We study the polarization efficiency (defined as the ratio of polarization to extinction) of stars in the background of the small, nearly spherical and isolated Bok globule CB4 to understand the grain alignment process. A decrease in…

Solar and Stellar Astrophysics · Physics 2015-06-17 Ajoy Barman , Himadri Sekhar Das

We present Spitzer infrared observations of the starless core L429. The IR images of this core show an absorption feature, caused by the dense core material, at wavelengths <= 70 micron. The core has a steep density profile, and reaches A_V…

Using recent dust continuum data, we generate the intrinsic ellipticity distribution of dense, starless molecular cloud cores. Under the hypothesis that the cores are all either oblate or prolate randomly-oriented spheroids, we show that a…

Astrophysics · Physics 2009-11-07 Charles L. Curry

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

Infrared photometry and spectroscopy (1-25 um) of background stars reddened by the Lupus molecular cloud complex are used to determine the properties of the grains and the composition of the ices before they are incorporated into…

The polarization of starlight and thermal dust emission from aligned non-spherical grains provides a powerful tool for tracing magnetic field morphologies and strengths in diffuse interstellar medium to star-forming regions, and…

Astrophysics of Galaxies · Physics 2025-07-11 Saikhom Pravash , Thiem Hoang , Archana Soam , Eun Jung Chung , Pham Ngoc Diep , Nguyen Bich Ngoc , Le Ngoc Tram
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