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Related papers: Turbulence in Zeeman Measurements from Molecular C…

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All molecular clouds are observed to be turbulent, but the origin, means of sustenance, and evolution of the turbulence remain debated. One possibility is that stellar feedback injects enough energy into the cloud to drive observed motions…

Astrophysics of Galaxies · Physics 2016-12-28 Ryan D. Boyden , Eric W. Koch , Erik W. Rosolowsky , Stella S. R. Offner

Complex turbulent motions of magnetized gas are ubiquitous in the interstellar medium. The source of this turbulence, however, is still poorly understood. Previous work suggests that compression caused by supernova shockwaves, gravity, or…

Astrophysics of Galaxies · Physics 2020-02-26 Ankush Mandal , Christoph Federrath , Bastian Körtgen

The orientations of filamentary molecular clouds in the Gould Belt and their local ICM (inter-cloud media) magnetic fields are studied using near-infrared dust extinction maps and optical stellar polarimetry data. These filamentary clouds…

Astrophysics of Galaxies · Physics 2015-06-17 Hua-bai Li , Min Fang , Thomas Henning , Jouni Kainulainen

We show that simulations of magnetohydrodynamic turbulence in the multiphase interstellar medium yield an $E/B$ ratio for polarized emission from Galactic dust in broad agreement with recent $Planck$ measurements. In addition, the $B$-mode…

Astrophysics of Galaxies · Physics 2018-07-12 Alexei G. Kritsuk , Raphael Flauger , Sergey D. Ustyugov

The currently most viable methods to estimate magnetic field strengths in molecular cloud cores are Zeeman measurements and the Chandrasekhar-Fermi (CF) method. The CF-method estimates magnetic field strengths from polarimetry and relies on…

Astrophysics · Physics 2007-05-23 F. Heitsch , P. S. Li

Observations of the properties of dense molecular clouds are critical in understanding the process of star-formation. One of the most important, but least understood, is the role of the magnetic fields. We discuss the possibility of using…

High Energy Astrophysical Phenomena · Physics 2014-12-16 A. W. Strong , C. Dickinson , E. J. Murphy

Crutcher, Hakobian, and Troland (2009) used OH Zeeman observations of four nearby molecular dark clouds to show that the ratio of mass to magnetic flux was smaller in the ~0.1 pc cores than in the ~1 pc envelopes, in contradiction to the…

Solar and Stellar Astrophysics · Physics 2015-05-14 R. M. Crutcher , N. Hakobian , T. H. Troland

Context. Observations of Zeeman split spectral lines represent an important approach to derive the structure and strength of magnetic fields in molecular clouds. In contrast to the uncertainty of the spectral line observation itself, the…

Astrophysics of Galaxies · Physics 2017-05-10 R. Brauer , S. Wolf , S. Reissl , F. Ober

We present results from two-dimensional numerical simulations of a supersonic turbulent flow in the plane of the galactic disk, incorporating shear, thresholded and discrete star formation (SF), self-gravity, rotation and magnetic fields. A…

Astrophysics · Physics 2009-10-28 T. Passot , E. Vazquez-Semadeni , A. Pouquet

{Magnetic fields exist on all scales in our Galaxy. There is a controversy about whether the magnetic fields in molecular clouds are preserved from the permeated magnetic fields in the interstellar medium (ISM) during cloud formation. We…

Astrophysics · Physics 2008-08-14 J. L. Han , J. S. Zhang

We present three numerical simulations of randomly driven, isothermal, non-magnetic, self-gravitating turbulence with different rms Mach numbers Ms and physical sizes L, but approximately the same value of the virial parameter, alpha approx…

Measurement of magnetic fields in dense molecular clouds is essential for understanding the fragmentation process prior to star formation. Radio interferometric observations of CCS 22.3 GHz emission, from the starless core TMC-1C, have been…

Astrophysics of Galaxies · Physics 2022-08-17 Atanu Koley , Nirupam Roy , Emmanuel Momjian , Anuj P. Sarma , Abhirup Datta

Turbulence is a complex physical process prevalent in modern physics, particularly in ionized environments like interstellar gas, where magnetic fields play a dynamic role. However, the precise influence of magnetic fields in such settings…

Astrophysics of Galaxies · Physics 2025-08-12 Guang-Xing Li , Mengke Zhao

Observations of nearby molecular clouds detect "shells", which are likely caused by winds from young main sequence stars. However, the progenitors of these observed features are not well characterized and the mass-loss rates inferred from…

Astrophysics of Galaxies · Physics 2015-10-07 S. S. R. Offner , H. G. Arce

(abridged) Together with gravity, turbulence, and stellar feedback, magnetic fields (B-fields) are thought to play a critical role in the evolution of molecular clouds and star formation processes. We aim to map the morphology and measure…

Perhaps the most intriguing result of Planck's dust-polarization measurements is the observation that the power in the E-mode polarization is twice that in the B mode, as opposed to pre-Planck expectations of roughly equal dust powers in E…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-26 Robert R. Caldwell , Chris Hirata , Marc Kamionkowski

We present the results of a new survey of 23 molecular clouds for the Zeeman effect in OH undertaken with the ATNF Parkes 64-m radio telescope and the NRAO Green Bank 43-m radio telescope. The Zeeman effect was clearly detected in the cloud…

Astrophysics · Physics 2009-11-06 Tyler L. Bourke , Philip C. Myers , Garry Robinson , A. R. Hyland

Density correlations unambiguously reveal the quantum nature of matter. Here, we study correlations between measurements of density in cold-atom clouds at different times at one position, and also at two separated positions. We take into…

Quantum Gases · Physics 2015-03-16 M. Kohnen , R. A. Nyman

The observed rapid onset of star formation in molecular clouds requires rapid formation of dense fragments which can collapse individually before being overtaken by global gravitationally-driven flows. Many previous investigations have…

Astrophysics · Physics 2009-11-13 F. Heitsch , L. Hartmann , A. Burkert , ;

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