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Related papers: Striations in molecular clouds: Streamers or MHD w…

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The origin of striations aligned along the local magnetic field direction in the translucent envelope of the Taurus molecular cloud is examined with new observations of 12CO and 13CO J=2-1 emission obtained with the 10~m submillimeter…

Astrophysics of Galaxies · Physics 2016-08-03 M. Heyer , P. F. Goldsmith , U. A. Yildiz , R. L. Snell , E. Falgarone , J. Pineda

Thin, magnetically aligned striations of relatively moderate contrast with the background are commonly observed in both atomic and molecular clouds. They are also prominent in MHD simulations with turbulent converging shocks. The simulated…

Astrophysics of Galaxies · Physics 2017-10-11 Che-Yu Chen , Zhi-Yun Li , Patrick K. King , Laura M. Fissel

The formation of molecular gas in interstellar clouds is a slow process, but is enhanced by gas compression. Magnetohydrodynamic (MHD) waves create compressed quasiperiodic linear structures, referred to as striations. Striations are…

Astrophysics of Galaxies · Physics 2023-05-10 R. Skalidis , K. Gkimisi , K. Tassis , G. V. Panopoulou , V. Pelgrims , A. Tritsis , P. F. Goldsmith

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

The MHD version of the adaptive mesh refinement (AMR) code, MG, has been employed to study the interaction of thermal instability, magnetic fields and gravity through 3D simulations of the formation of collapsing cold clumps on the scale of…

Astrophysics of Galaxies · Physics 2020-11-11 C. J. Wareing , J. M. Pittard , S. A. E. G. Falle

Molecular clouds (MCs) are highly structured and ``turbulent''. Colliding gas streams of atomic hydrogen have been suggested as a possible source of MCs, imprinting the filamentary structure as a consequence of dynamical and thermal…

Astrophysics · Physics 2009-11-13 F. Heitsch , A. Burkert , L. Hartmann , A. D. Slyz , J. E. G. Devriendt

Striations are diffuse, linear, quasi-periodic, and magnetized structures located in the outskirts of molecular clouds. These structures seem to play an important role during the earliest stages of star formation. Theoretical models suggest…

Astrophysics of Galaxies · Physics 2025-09-03 Raphael Skalidis , Konstantinos Tassis , Aris Tritsis , Paul F Goldsmith

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

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

{It has recently been proposed that giant molecular complexes form at the sites where streams of diffuse warm atomic gas collide at transonic velocities.} {We study the global statistics of molecular clouds formed by large scale colliding…

Astrophysics · Physics 2009-11-13 P. Hennebelle , R. Banerjee , E. Vazquez-Semadeni , R. Klessen , E. Audit

We present CO ($J = 1-0$) multi-line observations toward the L914 dark cloud in the vicinity of the Cygnus X region, using the 13.7 m millimeter telescope of the Purple Mountain Observatory (PMO). The CO observations reveal in the L914…

Astrophysics of Galaxies · Physics 2024-03-06 Li Sun , Xuepeng Chen , Min Fang , Shaobo Zhang , Yan Gong , Jiancheng Feng , Xuefu Li , Qing-Zeng Yan , Ji Yang

We present a comprehensive study of MHD waves and instabilities in a weakly ionised system, e.g., an interstellar molecular cloud. We determine all the critical wavelengths of perturbations across which the sustainable wave modes can change…

Solar and Stellar Astrophysics · Physics 2011-04-01 Telemachos Ch. Mouschovias , Glenn E. Ciolek , S. A. Morton

(Abridged) We present a series of decaying turbulence simulations that represent a cluster-forming clump within a molecular cloud, investigating the role of magnetic fields on the formation of potential star-forming cores. We present an…

Astrophysics · Physics 2007-11-07 David A. Tilley , Ralph E. Pudritz

We present ongoing hydrodynamic and MHD simulations of molecular cloud formation in spiral galaxies. The hydrodynamic results show the formation of molecular gas clouds where spiral shocks compress atomic gas to high densities. The spiral…

Astrophysics · Physics 2007-06-27 Clare Dobbs , Daniel Price , Ian Bonnell

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

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

It is believed that turbulence may have a significant impact on star formation and the dynamics and evolution of the molecular clouds in which this occurs. It is also known that non-ideal magnetohydrodynamic effects influence the nature of…

Astrophysics of Galaxies · Physics 2015-06-05 T. P. Downes

We carry out three-dimensional MHD simulations of star formation in turbulent, magnetized clouds, including ambipolar diffusion and feedback from protostellar outflows. The calculations focus on relatively diffuse clouds threaded by a…

Astrophysics · Physics 2009-11-13 Fumitaka Nakamura , Zhi-Yun Li

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

We study the linear evolution of small perturbations in self-gravitating fluid systems with magnetic fields. We consider wave-like perturbations to nonuniform filamentary and sheet-like hydrostatic equilibria in the presence of a uniform…

Astrophysics · Physics 2015-06-24 Curtis S. Gehman , Fred C. Adams , Richard Watkins
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