English
Related papers

Related papers: A Turbulent Model for the Interstellar Medium. II.…

200 papers

We analyze direct numerical simulations of large-scale dynamos in inhomogeneous nonhelically driven rotating turbulence with and without shear. The forcing is modulated so that the turbulent intensity peaks in the middle of the…

Plasma Physics · Physics 2025-05-02 Axel Brandenburg , Ethan T. Vishniac

We present a set of three-dimensional (3D) direct numerical simulations of incompressible decaying magnetohydrodynamic turbulence in which we investigate the influence of an external uniform magnetic field B_0. A parametric study in terms…

Fluid Dynamics · Physics 2009-11-13 Barbara Bigot , Sebastien Galtier , Helene Politano

Ambipolar diffusion (AD) is believed to be a crucial process for redistributing magnetic flux in the dense molecular gas that occurs in regions of star formation. We carry out numerical simulations of this process in regions of low…

Solar and Stellar Astrophysics · Physics 2015-05-30 Pak Shing Li , Christopher F. McKee , Richard I. Klein

The emergence of large-scale magnetic fields observed in the diffuse interstellar medium is explained by a turbulent dynamo. The underlying transport coefficients have previously been extracted from numerical simulations. So far, this was…

Astrophysics of Galaxies · Physics 2015-06-11 Oliver Gressel , Abhijit Bendre , Detlef Elstner

The evolution of large-scale magnetic fields in disk galaxies is investigated numerically. The gasdynamical simulations in a disk perturbed by spiral or bar potential are incorporated into the kinematic calculations of induction equations…

Astrophysics · Physics 2007-05-23 K. Otmianowska-Mazur , M. Chiba

We study the impact of compressibility on two-dimensional turbulent flows, such as those modeling astrophysical disks. We demonstrate that the direction of cascade undergoes continuous transition as the Mach number Ma increases, from…

Fluid Dynamics · Physics 2023-02-23 Itzhak Fouxon , Alexei G. Kritsuk , Michael Mond

Turbulence is the most common state of astrophysical flows. In typical astrophysical fluids, turbulence is accompanied by strong magnetic fields, which has a large impact on the dynamics of the turbulent cascade. Recently, there has been a…

Astrophysics · Physics 2011-05-10 Jungyeon Cho , A. Lazarian , Ethan Vishniac

We present the results of three-dimensional simulations of supersonic Euler turbulence with grid resolutions up to 1024^3 points. Our numerical experiments describe nonmagnetized driven turbulent flows with an isothermal equation of state…

Astrophysics · Physics 2008-11-26 Alexei G. Kritsuk , Rick Wagner , Michael L. Norman , Paolo Padoan

Recent fully nonlinear, kinetic three-dimensional simulations of magnetic reconnection [Daughton et al. 2011] evolve structures and exhibit dynamics on multiple scales, in a manner reminiscent of turbulence. These simulations of…

Plasma Physics · Physics 2015-06-15 E. Leonardis , S. C. Chapman , W. Daughton , V. Roytershteyn , H. Karimabadi

Astrophysical fluids, including interstellar and interplanetary medium, are magnetized and turbulent. Their appearance, evolution, and overall properties are determined by the magnetic turbulence that stirs it. We argue that examining…

Astrophysics · Physics 2009-11-13 A. Lazarian , A. Beresnyak , H. Yan , M. Opher , Y. Liu

Magnetic field embedded in a perfectly conducting fluid preserves its topology for all time. Although ionized astrophysical objects, like stars and galactic disks, are almost perfectly conducting, they show indications of changes in…

Astrophysics of Galaxies · Physics 2010-03-16 A. Lazarian , G. Kowal , E. Vishniac , K. Kulpa-Dubel , K. Otmianowska-Mazur

A Hamiltonian two-field gyrofluid model is used to investigate the dynamics of an electron-ion collisionless plasma subject to a strong ambient magnetic field, within a spectral range extending from the magnetohydrodynamic (MHD) scales to…

Plasma Physics · Physics 2024-06-10 T. Passot , S. S. Cerri , C. Granier , D. Laveder , P. L. Sulem , E. Tassi

Compressible magnetohydrodynamic (MHD) turbulence is ubiquitous in astrophysical phenomena ranging from the intergalactic to the stellar scales. In studying them, numerical simulations are nearly inescapable, due to the large degree of…

Fluid Dynamics · Physics 2016-07-27 Dimitar G Vlaykov , Philipp Grete , Wolfram Schmidt , Dominik R G Schleicher

We demonstrate that the formation of collapsing cores in subcritical clouds is accelerated by nonlinear flows, by performing three-dimensional non-ideal MHD simulations. An initial random supersonic (and trans-Alfvenic) turbulent-like flow…

Astrophysics · Physics 2009-11-13 Takahiro Kudoh , Shantanu Basu

Formation of interstellar clouds as a consequence of thermal instability is studied using two-dimensional two-fluid magnetohydrodynamic simulations. We consider the situation of converging, supersonic flows of warm neutral medium in the…

Astrophysics of Galaxies · Physics 2015-05-14 Tsuyoshi Inoue , Shu-ichiro Inutsuka

Magnetic fields on the order of 100 $\mu$G observed in young supernova remnants cannot be amplified by shock compression alone. To investigate the amplification caused by turbulent dynamo, we perform three-dimensional MHD simulations of the…

Astrophysics of Galaxies · Physics 2022-12-28 Yue Hu , Siyao Xu , James M. Stone , Alex Lazarian

The strengths of magnetic fields in interstellar gas clouds are obtained through observations of the circular polarization of spectral line radiation. Irregularities in this magnetic field may be present due to turbulence, waves or perhaps…

Astrophysics · Physics 2009-10-31 W. D. Watson , D. S. Wiebe , R. M. Crutcher

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

Motivated by the observed differences in the nebular emission of nearby and high-redshift galaxies, we carry out a set of direct numerical simulations of turbulent astrophysical media exposed to a UV background. The simulations assume a…

Astrophysics of Galaxies · Physics 2017-11-15 William J. Gray , Evan Scannapieco

We discuss HD and MHD compressible turbulence as a cloud-forming and cloud-structuring mechanism in the ISM. Results from a numerical model of the turbulent ISM at large scales suggest that the phase-like appearance of the medium, the…

Astrophysics · Physics 2007-05-23 Enrique Vazquez-Semadeni