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Related papers: Helical Fields and Filamentary Molecular Clouds

200 papers

The BLASTPol observations of Vela C have provided the most detailed characterization of the polarization fraction $p$ and dispersion in polarization angles $S$ for a molecular cloud. We compare the observed distributions of $p$ and $S$ with…

Astrophysics of Galaxies · Physics 2018-01-10 Patrick K. King , Laura M. Fissel , Che-Yu Chen , Zhi-Yun Li

Filamentary molecular clouds are regarded as the place where newborn stars are formed. In particular, a hub region, a place where it appears as if several filaments are colliding, often indicates active star formation. To understand the…

Astrophysics of Galaxies · Physics 2023-09-06 Raiga Kashiwagi , Kazunari Iwasaki , Kohji Tomisaka

The ubiquitous presence of filamentary structures in the interstellar medium asks for an unbiased characterization of their properties including a stability analysis. We propose a novel technique to measure the spectrum of filaments in any…

Astrophysics of Galaxies · Physics 2018-12-19 Volker Ossenkopf-Okada , Rodion Stepanov

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

Synchrotron-emitting, nonthermal filaments (NTFs) have been observed near the Galactic center for nearly four decades, yet their physical origin remains unclear. Here we investigate the possibility that NTFs are produced by the destruction…

Astrophysics of Galaxies · Physics 2020-12-16 Eric R. Coughlin , C. J. Nixon , Adam Ginsburg

Using self-consistent magnetohydrodynamic (MHD) simulations, we explore the hypothesis that nonlinear MHD waves dominate the internal dynamics of galactic molecular clouds. We employ an isothermal equation of state and allow for…

Astrophysics · Physics 2016-08-30 Charles F. Gammie , Eve C. Ostriker

Polarization carries information about the magnetic fields in interstellar clouds. The observations of polarized dust emission are used to study the role of magnetic fields in the evolution of molecular clouds and the initial phases of…

Astrophysics of Galaxies · Physics 2015-05-13 V. -M. Pelkonen , M. Juvela , P. Padoan

Diffuse striations in molecular clouds are preferentially aligned with local magnetic fields whereas dense filaments tend to be perpendicular to them. When and why this transition occurs remain uncertain. To explore the physics behind this…

Astrophysics of Galaxies · Physics 2016-10-05 Che-Yu Chen , Patrick K. King , Zhi-Yun Li

Filamentary molecular clouds are an essential intermediate stage in the star formation process. To test whether these structures are universal throughout cosmic star formation history, it is crucial to study low-metallicity environments…

We present high resolution simulations of two-fluid (ion-neutral) MHD turbulence with resolutions as large as 512^3. The simulations are supersonic and mildly sub-Alfvenic, in keeping with the conditions present in molecular clouds. Such…

Astrophysics of Galaxies · Physics 2015-06-16 Chad D. Meyer , Dinshaw S. Balsara , Blakesley Burkhart , Alex Lazarian

Most molecular clouds are filamentary or elongated. Among those forming low-mass stars, their long axes tend to be either parallel or perpendicular to the large-scale (10-100 pc) magnetic field (B-field) in the surrounding inter cloud…

Astrophysics of Galaxies · Physics 2015-10-27 Hua-bai Li , Ka Ho Yuen , Frank Otto , Po Kin Leung , T. K. Sridharan , Qizhou Zhang , Hauyu Liu , Ya-Wen Tang , Keping Qiu

Recent studies of the diffuse parts of molecular clouds have revealed the presence of parallel, ordered low-density filaments termed striations. Flows along magnetic field lines, Kelvin-Helmholtz instabilities and hydromagnetic waves are…

Astrophysics of Galaxies · Physics 2018-10-17 Aris Tritsis , Christoph Federrath , Nicola Schneider , Konstantinos Tassis

We have studied the filaments extracted from the column density maps of the nearby Lupus 1, 3, and 4 molecular clouds, derived from photometric maps observed with the Herschel satellite. Filaments in the Lupus clouds have quite low column…

In paper I, we obtained an equation for the evolution of density inhomogeneities in a radiation dominated universe when they are affected by magnetic fields. In this second paper we apply this equation to the case in which the subjacent…

Astrophysics · Physics 2016-08-30 E. Florido , E. Battaner

We explore whether observed molecular clouds could include a substantial population of unbound clouds. Using simulations which include only turbulence and gravity, we are able to match observed relations and naturally reproduce the observed…

Astrophysics of Galaxies · Physics 2014-03-05 Rachel L. Ward , James Wadsley , Alison Sills

Fragmentation process in a cylindrical magnetized cloud is studied with the nested grid method. The nested grid scheme use 15 levels of grids with different spatial resolution overlaid subsequently, which enables us to trace the evolution…

Astrophysics · Physics 2015-06-24 Kohji Tomisaka

We theoretically study the conformations of a helical semi-flexible filament confined to a flat surface. This squeezed helix exhibits a variety of unexpected shapes resembling circles, waves or spirals depending on the material parameters.…

Biological Physics · Physics 2017-02-16 Lila Bouzar , Martin Michael Müller , Pierre Gosselin , Igor M. Kulić , Hervé Mohrbach

We present findings of 3D filamentary structures in the Smith Cloud, a high-velocity cloud (HVC) located at $l=38^{\circ}$, $b=-13^{\circ}$. We use data from the Galactic Arecibo L-Band Feed Array \ion{H}{i} (GALFA-\ion{H}{i}) along with…

Astrophysics of Galaxies · Physics 2025-05-06 Colin Holm-Hansen , M. E. Putman , D. A. Kim

We study the effect of a magnetic field on the behaviour of a conducting elastic rod subject to a novel set of boundary conditions that, in the case of a transversely isotropic rod, give rise to exact helical post-buckling solutions. The…

Dynamical Systems · Mathematics 2015-06-04 J. Valverde , G. H. M. van der Heijden

We use ensemble machine learning algorithms to study the evolution of magnetic fields in magnetohydrodynamic (MHD) turbulence that is helically forced. We perform direct numerical simulations of helically forced turbulence using mean field…

Solar and Stellar Astrophysics · Physics 2019-09-11 Farrukh Nauman , Joonas Nättilä