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相关论文: Temporal evolution of magnetic molecular shocks I.…

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We have developed a novel computer code designed to follow the evolution of cosmic-ray modified shocks, including the full momentum dependence of the particles for a realistic diffusion coefficient model. In this form the problem is…

天体物理学 · 物理学 2009-10-31 Hyesung Kang , T. W. Jones , R. J. LeVeque , K. M. Shyue

C-type shocks are believed to be ubiquitous in turbulent molecular clouds thanks to ambipolar diffusion. We investigate whether the drag instability in 1D isothermal C-shocks, inferred from the local linear theory of Gu & Chen, can appear…

星系天体物理 · 物理学 2022-08-23 Pin-Gao Gu , Che-Yu Chen , Emma Shen , Chien-Chang Yen , Min-Kai Lin

The character of star formation is intimately related to the supersonic magnetohydrodynamic (MHD) turbulent dynamics of the molecular clouds in which stars form. A significant amount of the turbulent energy dissipates in low velocity…

星系天体物理 · 物理学 2015-10-09 Andrew Lehmann , Mark Wardle

The molecular component of the Galaxy is comprised of turbulent, magnetized clouds, many of which are self-gravitating and form stars. To understand how these clouds' evolution may depend on their level of turbulence, mean magnetization,…

天体物理学 · 物理学 2009-10-31 Eve C. Ostriker , Charles F. Gammie , James M. Stone

The evolutionary conditions for the dissipative continuous magnetohydrodynamic (MHD) shocks are studied. We modify Hada's approach in the stability analysis of the MHD shock waves. The matching conditions between perturbed shock structure…

天体物理学 · 物理学 2008-11-26 Tsuyoshi Inoue , Shu-ichiro Inutsuka

We study effect of magnetic field on massive dense core formation in colliding unequal molecular clouds by performing magnetohydrodynamic simulations with sub-parsec resolution (0.015 pc) that can resolve the molecular cores. Initial clouds…

星系天体物理 · 物理学 2020-07-23 Nirmit Sakre , Asao Habe , Alex R. Pettitt , Takashi Okamoto

Shocks waves are a ubiquitous feature of many astrophysical plasma systems, and an important process for energy dissipation and transfer. The physics of these shock waves are frequently treated/modeled as a collisional, fluid MHD…

等离子体物理 · 物理学 2021-11-17 Colby C. Haggerty , Antoine Bret , Damiano Caprioli

We use 3D numerical MHD simulations to follow the evolution of cold, turbulent, gaseous systems with parameters representing GMC conditions. We study three cloud simulations with varying mean magnetic fields, but identical initial velocity…

天体物理学 · 物理学 2008-11-26 Eve C. Ostriker , James M. Stone , Charles F. Gammie

We employ the first fully three-dimensional simulation to study the role of magnetic fields and ion-neutral friction in regulating gravitationally-driven fragmentation of molecular clouds. The cores in an initially subcritical cloud develop…

天体物理学 · 物理学 2008-11-26 Takahiro Kudoh , Shantanu Basu , Youichi Ogata , Takashi Yabe

We investigate the long-time evolution of magnetic fields generated by the two-stream instability at ultra- and sub-relativistic astrophysical collisionless shocks. Based on 3D PIC simulation results, we introduce a 2D toy model of…

We study the evolution of QCD phase transition-generated magnetic fields in freely decaying MHD turbulence of the expanding Universe. We consider a magnetic field generation model that starts from basic non-perturbative QCD theory and…

宇宙学与河外天体物理 · 物理学 2012-10-18 Alexander G. Tevzadze , Leonard Kisslinger , Axel Brandenburg , Tina Kahniashvili

We report results of a three dimensional, high resolution (up to 512^3) numerical investigation of supersonic compressible magnetohydrodynamic turbulence. We consider both forced and decaying turbulence. The model parameters are appropriate…

天体物理学 · 物理学 2009-10-30 James M. Stone , Eve C. Ostriker , Charles F. Gammie

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)…

In shock precursors populated by accelerated cosmic rays (CR), the CR return current instability is believed to significantly enhance the pre-shock perturbations of magnetic field. We have obtained fully-nonlinear exact ideal MHD solutions…

星系天体物理 · 物理学 2016-10-11 M. A. Malkov , R. Z. Sagdeev , P. H. Diamond

The inverse cascade in MHD turbulence plays a crucial role in various astrophysical processes such as galaxy cluster formation, solar and stellar dynamo mechanisms, and the evolution of primordial magnetic fields in the early universe. A…

宇宙学与河外天体物理 · 物理学 2026-02-02 Jiyao Zhang , Axel Brandenburg

Theory of magnetic deflagration taking into account dipolar-controlled spin tunneling has been applied to the realistic model of molecular magnet Mn_12 Ac. At small transverse field, the front speed v has tunneling maxima on the bias field…

统计力学 · 物理学 2014-01-07 D. A. Garanin , Saaber Shoyeb

Molecular Dynamic (MD) approach is applied to study the converging cylindrical shock waves in a dense Lennard-Jones (LJ) fluid. MD method is based on tracking of the atom motions and hence it has an fundamental advantages over hydrodynamic…

计算物理 · 物理学 2009-04-23 V. Zhakhovskii , K. Nishihara , M. Abe

We study a relativistic collisionless electron-positron shock propagating into an unmagnetized ambient medium using 2D particle-in-cell simulations of unprecedented duration and size. The shock generates intermittent magnetic structures of…

高能天体物理现象 · 物理学 2024-03-12 Daniel Groselj , Lorenzo Sironi , Anatoly Spitkovsky

We discuss high-resolution simulations of one-dimensional, plane-parallel shock waves with mean speeds between 150 and 240 km/s propagating into gas with Alfven velocities up to 40 km/s and outline the conditions under which these radiative…

天体物理学 · 物理学 2009-10-30 Paul A. Kimoto , David F. Chernoff

We formulate a coarse-graining approach to the dynamics of magnetohydrodynamic (MHD) fluids at a continuum of length-scales. In this methodology, effective equations are derived for the observable velocity and magnetic fields…

太阳与恒星天体物理 · 物理学 2017-04-05 Hussein Aluie