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Related papers: Helical Fields and Filamentary Molecular Clouds

200 papers

{Filaments are ubiquitous in the interstellar medium as recently emphasized by Herschel, yet their physical origin remains elusive} {It is therefore important to understand the physics of molecular clouds to investigate how filaments form…

Astrophysics of Galaxies · Physics 2015-06-16 Patrick Hennebelle

Recent observations near the Galactic Centre have found several molecular filaments displaying striking helically-wound morphology, which are collectively known as "molecular tornadoes." We investigate the equilibrium structure of these…

Astrophysics of Galaxies · Physics 2017-07-26 Kelvin Au , Jason D. Fiege

The physical properties of the so-called Ostriker isothermal, non-rotating filament have been classically used as benchmark to interpret the stability of the filaments observed in nearby clouds. However, such static picture seems to…

Astrophysics of Galaxies · Physics 2015-06-22 S. Recchi , A. Hacar , A. Palestini

To what extent magnetic fields affect how molecular clouds (MCs) fragment and create dense structures is an open question. We present a numerical study of cloud fragmentation using the SILCC-Zoom simulations. These simulations follow the…

Astrophysics of Galaxies · Physics 2023-07-26 S. Ganguly , S. Walch , D. Seifried , S. D. Clarke , M. Weis

Filamentary structures are recognized as a fundamental component of interstellar molecular clouds in observations by the Herschel satellite. These filaments, especially massive filaments, often extend in a direction perpendicular to the…

Astrophysics of Galaxies · Physics 2021-06-04 Raiga Kashiwagi , Kohji Tomisaka

We examine the linear stability of an isothermal filamentary cloud permeated by a perpendicular magnetic field. Our model cloud is assumed to be supported by gas pressure against the self-gravity in the unperturbed state. For simplicity,…

Astrophysics of Galaxies · Physics 2017-10-11 Tomoyuki Hanawa , Takahiro Kudoh , Kohji Tomisaka

We review recent results from numerical simulations and related models of MHD turbulence in the interstellar medium (ISM) and in molecular clouds. We discuss the implications of turbulence for the processes of cloud formation and evolution,…

Astrophysics · Physics 2007-05-23 E. Vazquez-Semadeni , E. C. Ostriker , T. Passot , C. F. Gammie , J. M. Stone

Magnetic fields are ubiquitously observed in the interstellar medium (ISM) of present-day star-forming galaxies with dynamically relevant energy densities. Using three-dimensional magneto-hydrodynamic (MHD) simulations of the supernova (SN)…

Filamentary structures are ubiquitous in the interstellar medium, yet their formation, internal structure, and longevity have not been studied in detail. We report the results from a comprehensive numerical study that investigates the…

Astrophysics of Galaxies · Physics 2015-11-18 Wladimir Banda-Barragán , Ross Parkin , Christoph Federrath , Roland Crocker , Geoffrey Bicknell

Stars form in highly-magnetised, supersonic turbulent molecular clouds. Many of the tools and models that we use to carry out star formation studies rely upon the assumption of cloud isotropy. However, structures like high-density filaments…

Astrophysics of Galaxies · Physics 2020-01-08 James R. Beattie , Christoph Federrath

We describe the results of a sequence of simulations of gravitational collapse in a turbulent magnetized region. The parameters are chosen to be representative of molecular cloud material. We find that several protostellar cores and…

Astrophysics · Physics 2009-11-06 D. Balsara , D. Ward-Thompson , R. M. Crutcher

In recent years, there were studies on the omnipresence and structures of filaments in star-forming regions, and the role of their fragmentation in the process of star formation. However, only a few studies analysed the evolution of…

Astrophysics of Galaxies · Physics 2018-06-07 Roxana-Adela Chira

Observations of the cores of nearby galaxy clusters show H$\alpha$ and molecular emission line filaments. We argue that these are the result of {\em local} thermal instability in a {\em globally} stable galaxy cluster core. We present…

Astrophysics of Galaxies · Physics 2015-05-18 Prateek Sharma , Ian J. Parrish , Eliot Quataert

Following an approach initially outlined by McKee & Holliman, we investigate the structure and stability of dense, starless molecular cloud cores. We model those as spherical clouds in hydrostatic equilibrium and supported against gravity…

Astrophysics · Physics 2007-05-23 J. Kauffmann , F. Bertoldi

The gravitational instability of a filamentary molecular cloud in non-ideal magnetohydrodynamics is investigated. The filament is assumed to be in hydrostatic equilibrium. We add the effect of ambipolar diffusion to the filament which is…

Astrophysics of Galaxies · Physics 2016-12-21 Mohammad Hosseinirad , Kazem Naficy , Shahram Abbassi , Mahmood Roshan

We have used the AMR hydrodynamic code, MG, to perform idealised 3D MHD simulations of the formation of clumpy and filamentary structure in a thermally unstable medium without turbulence. A stationary thermally unstable spherical diffuse…

Astrophysics of Galaxies · Physics 2016-03-23 C. J. Wareing , J. M. Pittard , S. A. E. G. Falle , S. Van Loo

Filamentary structures are ubiquitous in observations of real molecular clouds, and also in simulations of turbulent, self-gravitating gas. However, making comparisons between observations and simulations is complicated by the difficulty of…

Astrophysics of Galaxies · Physics 2020-10-14 F. D. Priestley , A. P. Whitworth

This study is motivated by recent observations on ubiquitous interstellar density filaments and guided by modern theories of compressible magnetohydrodynamic (MHD) turbulence. The interstellar turbulence shapes the observed density…

Astrophysics of Galaxies · Physics 2019-08-07 Siyao Xu , Suoqing Ji , A. Lazarian

Polarized 850 micron thermal emission data of the region OMC-3 in the Orion A molecular cloud are presented. These data, taken in 1998 with the SCUBA polarimeter mounted on the James Clerk Maxwell Telescope, have been re-reduced using…

Astrophysics · Physics 2009-11-06 B. C. Matthews , C. D. Wilson , J. D. Fiege

Polarimeric maps have been used on the characterization of the magnetic field in molecular clouds. However, it is difficult to determine the 3-dimensional properties of these regions from the projected maps. In that case, numerical…

Astrophysics · Physics 2008-12-23 D. Falceta-Goncalves , A. Lazarian , G. Kowal