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Related papers: Grain Alignment in Molecular Clouds

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The formation of molecular clouds, which serve as stellar nurseries in galaxies, is poorly understood. A class of cloud formation models suggests that a large-scale galactic magnetic field is irrelevant at the scale of individual clouds,…

Astrophysics of Galaxies · Physics 2011-11-14 Hua-bai Li , Thomas Henning

During the past decade the dynamical importance of magnetic fields in molecular clouds has been increasingly recognized, as observational evidence has accumulated. However, how a magnetic field affect star formation is still unclear.…

Astrophysics of Galaxies · Physics 2020-09-15 C. Y. Law , H. -b. Li , Z. Cao , C. -Y. Ng

The linear polarization of thermal dust emission provides a powerful tool to probe interstellar and circumstellar magnetic fields, because aspherical grains tend to align themselves with magnetic field lines. While the Radiative Alignment…

Three-dimensional magnetic fields (3D B-fields) are essential to understand the formation and evolution of the interstellar medium and multi-scale star formation; however, the accurate measurement of 3D B-fields is still challenging. The…

Astrophysics of Galaxies · Physics 2025-10-09 Bao Truong , Thiem Hoang , Nguyen Bich Ngoc , Nguyen Chau Giang , Le Ngoc Tram , Ngan Le

Magnetic fields play such essential roles in star formation as transporting angular momentum and driving outflows from a star-forming cloud, thereby controlling the formation efficiency of a circumstellar disc and also multiple stellar…

Astrophysics of Galaxies · Physics 2021-02-03 Daisuke Nakauchi , Kazuyuki Omukai , Hajime Susa

The propensity of molecules to spatially align along the polarization vector of intense, pulsed light fields is related to readily-accessible parameters (molecular polarizabilities, moment of inertia, peak intensity of the light and its…

Atomic Physics · Physics 2009-11-06 S. Banerjee , D. Mathur , G. Ravindra Kumar

We apply the theory of radiative torque (RAT) alignment for studying protoplanetary disks around a T-Tauri star and perform 3D radiative transfer calculations to provide the expected maps of polarized radiation to be compared with…

Earth and Planetary Astrophysics · Physics 2017-04-19 Ryo Tazaki , Alexandre Lazarian , Hideko Nomura

We expand our study on the dispersion of polarization angles in molecular clouds. We show how the effect of signal integration through the thickness of the cloud as well as across the area subtended by the telescope beam inherent to dust…

Astrophysics of Galaxies · Physics 2014-11-20 Martin Houde , John E. Vaillancourt , Roger H. Hildebrand , Shadi Chitsazzadeh , Larry Kirby

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

We present a detailed study of the magnetic field structure in the G111 molecular cloud, a ring-like filamentary cloud within the NGC 7538 region. We utilized interstellar dust polarization from the Planck telescope to trace large-scale…

With the high-resolution spectroscopy now available in the optical and satellite UV, it is possible to determine the neutral/ionized column density ratios for several different elements in a single cloud. Assuming ionization equilibrium for…

Astrophysics · Physics 2009-11-06 Joseph C. Weingartner , B. T. Draine

Observations indicate that molecular clouds are strongly magnetized, and that magnetic fields influence the formation of stars. A key observation supporting the conclusion that molecular clouds are significantly magnetized is that the…

The ability to use external magnetic fields to influence the microstructure in polycrystalline materials has potential applications in microstructural engineering. To explore this potential and to understand the complex interactions between…

Materials Science · Physics 2019-04-03 R. Backofen , K. R. Elder , A. Voigt

The properties of interstellar grains can now be defined by a rapidly growing wealth of observational data. We rely upon models to combine these data with unobserved properties such as the size distribution of grains, their structure and…

Astrophysics · Physics 2007-05-23 Adolf N. Witt

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

We calculate the formation of dust clouds in atmospheres of giant gas-planets. The chemical structure and the evolution of the grain size distribution in the dust cloud layer is discussed based on a consistent treatment of seed formation,…

Astrophysics · Physics 2007-11-26 Christiane Helling

I review some steps in the conversion of molecular cloud gas into stars and planets, with an emphasis in this presentation on the early stage molecular cloud fragmentation that leads to elongated filaments/ribbons. Magnetic fields can play…

Astrophysics of Galaxies · Physics 2017-01-11 Shantanu Basu

Due to the continuous developments in polarimetric instrumentation, which will become even more dramatic in the near future with the availability of new generation solar telescopes, we are now severely confronted with a variety of new…

Solar and Stellar Astrophysics · Physics 2011-03-29 Luca Belluzzi

Collisions of gas particles with a drifting grain give rise to a mechanical torque on the grain. Recent work by Lazarian & Hoang showed that mechanical torques might play a significant role in aligning helical grains along the interstellar…

Astrophysics of Galaxies · Physics 2016-02-16 Indrajit Das , Joseph C. Weingartner

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
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