arXiv 1111.09752011-11-03astro-ph.SRphysics.plasm-ph

Modeling Poynting flux vs. kinetic-energy dominated jets

Martín Huarte-Espinosa, Adam Frank, Eric G. Blackman

备注：: 2 pages, 1 figure to appear in the proceedings of the "Magnetic Fields in the Universe III" meeting, Zakopane, PL

英文摘要：

We present 3D-MHD AMR simulations of Poynting flux dominated (PFD) jets formed by injection of magnetic energy. We compare their evolution with a hydrodynamic jet which is formed by injecting kinetic energy with the same energy flux than the PFD jets. We predict characteristic emission distributions for each of these jets. Current-driven perturbations in PFD jets are amplified by both cooling and rotation for the regimes studied: Shocks and thermal pressure support are weakened by cooling, making the jets more susceptible to kinking. Rotation amplifies the toroidal magnetic field which also exacerbates the kink instability.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

阅读原文

阅读 PDF ↗

arXiv 页面 ↗HTML 原文 ↗

本文内容

英文摘要相关论文

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

继续探索

相关论文

YSO喷流的三维建模II：由盘-磁层相互作用驱动的吸积-fed、恒星锚定的Poynting喷流，由低密度极性腔体产生

Modeling YSO Jets in 3D II: Accretion-Fed, Star-Anchored Poynting Jets in the Low-Density Polar Cavity Powered by Disk-Magnetosphere Interaction

University of Virginia（弗吉尼亚大学）；Virginia Institute of Theoretical Astronomy, University of Virginia（弗吉尼亚大学理论天体物理研究所）；University of Nevada, Las Vegas（内华达大学拉斯维加斯分校）；Nevada Center for Astrophysics, University of Nevada, Las Vegas（内华达大学拉斯维加斯分校内华达天体物理学中心）；University of Florida（佛罗里达大学）

本研究通过三维磁流体动力学模拟，揭示了由盘-磁层相互作用驱动的低密度极性腔体中磁性主导的Poynting喷流形成机制，与传统磁塔机制相比，该模型展示了恒星磁层对对称喷流发射的促进作用。

2026-02-16astro-ph.EPastro-ph.SR

Evolution of the Relativistic Plasmoid-Chain in the Poynting-Dominated Plasma

In this paper, we investigate the evolution of the plasmoid-chain in a Poynting-dominated plasma. We model the relativistic current sheet with cold background plasma using the relativistic resistive magnetohydrodynamic approximation, and solve its temporal evolution numerically. We perform various calculations using different magnetization parameters of the background plasma and different Lundquist numbers. Numerical results show that the initially induced plasmoid triggers a secondary tearing instability, which gradually fills the current sheet with plasmoids, as has also been observed in the…

2013-07-22astro-ph.EPastro-ph.HEastro-ph.SR

Strong Coupling of Alfvén and Fast Modes in Compressible Relativistic Magnetohydrodynamic Turbulence in Magnetically-Dominated Plasmas

In this paper, we report our detailed analysis of the new strong-coupling regime between Alfvén and fast modes in Poynting-dominated plasma turbulence, reported in our previous work Takamoto & Lazarian (2016), which is an important effect for many relativistic plasma phenomena, and calls for new theories of Poynting-dominated MHD turbulence. We performed numerical simulations of relativistic MHD turbulence in isothermal plasmas, and analyzed the ratio of fast to Alfvén mode energy. We found that the increase of the fast mode with the background $σ$-parameter can be observed even in isothermal …

2017-09-04astro-ph.HEastro-ph.SRphysics.flu-dyn

On the structure and stability of magnetic tower jets

Modern theoretical models of astrophysical jets combine accretion, rotation, and magnetic fields to launch and collimate supersonic flows from a central source. Near the source, magnetic field strengths must be large enough to collimate the jet requiring that the Poynting flux exceeds the kinetic-energy flux. The extent to which the Poynting flux dominates kinetic energy flux at large distances from the engine distinguishes two classes of models. In magneto-centrifugal launch (MCL) models, magnetic fields dominate only at scales $\lesssim 100$ engine radii, after which the jets become hydrodyn…

2012-09-07astro-ph.SR

关于具有有限庞加莱通量的喷流的聚焦性质

On the collimation properties of jets with finite Poynting flux launched from Keplerian accretion discs

University of Cambridge（剑桥大学）；Univ. Grenoble Alpes, CNRS, IPAG（格勒诺布尔阿尔卑斯大学，法国国家科学研究中心，天体物理学与行星学研究所）；INAF - Osservatorio Astrofisico di Torino（意大利国家天体物理研究所都灵天文台）

研究了磁化凯普勒吸积盘喷流的聚焦机制，发现自相似性并非必要，喷流在远距离产生稳定的再聚焦激波，影响喷流形状和加速效率。

2026-03-29astro-ph.HEastro-ph.SR

Laboratory experiments and simulations on jets

Astrophysical jets have been studied with observations, theoretical models and numerical simulations for decades. Recently, supersonic magnetized jets have been formed in laboratory experiments of high-energy density plasmas. I will review these studies and discuss the experimental setup that has been used to form millimeter-scale jets driven by strong toroidal magnetic fields in a MAGPIE generator. The physical conditions of these experiments are such that they can be scaled to astrophysical scenarios. These laboratory jets provide insights on the underlying physics of magnetic tower jets and…

2011-11-17astro-ph.SRphysics.plasm-ph

更多相关论文收起更多论文

Compressible Relativistic Magnetohydrodynamic Turbulence in Magnetically-Dominated Plasmas And Implications for A Strong-Coupling Regime

In this Letter, we report compressible mode effects on relativistic magnetohydrodynamic (RMHD) turbulence in Poynting-dominated plasmas using 3-dimensional numerical simulations. We decomposed fluctuations in the turbulence into 3 MHD modes (fast, slow, and Alfvén) following the procedure mode decomposition in (Cho & Lazarian 2002), and analyzed their energy spectra and structure functions separately. We also analyzed the ratio of compressible mode to Alfvén mode energy with respect to its Mach number. We found the ratio of compressible mode increases not only with the Alfvén Mach number but w…

2016-10-17astro-ph.HEastro-ph.SRphysics.flu-dyn

Experimental Studies of Magnetically Driven Plasma Jets

We present experimental results on the formation of supersonic, radiatively cooled jets driven by pressure due to the toroidal magnetic field generated by the 1.5 MA, 250 ns current from the MAGPIE generator. The morphology of the jet produced in the experiments is relevant to astrophysical jet scenarios in which a jet on the axis of a magnetic cavity is collimated by a toroidal magnetic field as it expands into the ambient medium. The jets in the experiments have similar Mach number, plasma beta and cooling parameter to those in protostellar jets. Additionally the Reynolds, magnetic Reynolds …

2010-12-10astro-ph.SRphysics.plasm-ph

Modelling magnetically dominated and radiatively cooling jets

Using 3D-MHD Eulerian-grid numerical simulations, we study the formation and evolution of rising magnetic towers propagating into an ambient medium. The towers are generated from a localized injection of pure magnetic energy. No rotation is imposed on the plasma. We compare the evolution of a radiatively cooling tower with an adiabatic one, and find that both bend due to pinch instabilities. Collimation is stronger in the radiative cooling case; the adiabatic tower tends to expand radially. Structural similarities are found between these towers and the millimeter scale magnetic towers produced…

2010-11-19astro-ph.SRphysics.plasm-ph

Rotating Solar Jets in Simulations of Flux Emergence with Thermal Conduction

We study the formation of coronal jets through numerical simulation of the emergence of a twisted magnetic flux rope into a pre-existing open magnetic field. Reconnection inside the emerging flux rope in addition to that between the emerging and pre-existing fields give rise to the violent eruption studied. The simulated event closely resembles the coronal jets ubiquitously observed by Hinode/XRT and demonstrates that heated plasma is driven into the extended atmosphere above. Thermal conduction implemented in the model allows us to qualitatively compare simulated and observed emission from su…

2014-06-09astro-ph.SR

Efficient Production of High-energy Nonthermal Particles during Magnetic Reconnection in a Magnetically-dominated Ion-Electron Plasma

Magnetic reconnection is a leading mechanism for dissipating magnetic energy and accelerating nonthermal particles in Poynting-flux dominated flows. In this letter, we investigate nonthermal particle acceleration during magnetic reconnection in a magnetically-dominated ion-electron plasma using fully kinetic simulations. For an ion-electron plasma with the total magnetization $σ_0=B^2/(4πn(m_i+m_e)c^2)$, the magnetization for each species is $σ_i \sim σ_0$ and $σ_e \sim (m_i/m_e) σ_0$, respectively. We have studied the magnetically dominated regime by varying $σ_{e} = 10^3 - 10^5$ with initial…

2016-01-18astro-ph.HEastro-ph.SRphysics.plasm-ph

On Poynting-Flux-Driven Bubbles and Shocks Around Merging Neutron Star Binaries

Merging binaries of compact relativistic objects (neutron stars and black holes) are thought to be progenitors of short gamma-ray bursts and sources of gravitational waves, hence their study is of great importance for astrophysics. Because of the strong magnetic field of one or both binary members and high orbital frequencies, these binaries are strong sources of energy in the form of Poynting flux (e.g., magnetic-field-dominated outflows, relativistic leptonic winds, electromagnetic and plasma waves). The steady injection of energy by the binary forms a bubble (or a cavity) filled with matter…

2012-12-17astro-ph.COastro-ph.HEastro-ph.SR

Untwisting Jets Related to Magnetic Flux Cancellation

The rotational motion of solar jets is believed to be a signature of the untwisting process resulting from magnetic reconnection, which takes place between twisted closed magnetic loops (i.e., magnetic flux ropes) and open magnetic field lines. The identification of the pre-existing flux rope, and the relationship between the twist contained in the rope and the number of turns the jet experiences, are then vital in understanding the jet-triggering mechanism. In this paper, we will perform a detailed analysis of imaging, spectral and magnetic field observations of four homologous jets, among wh…

2017-11-16astro-ph.SR

Analytical Solution of Magnetically Dominated Astrophysical Jets and Winds: Jet Launching, Acceleration, and Collimation

We present an analytical solution of a highly magnetized jet/wind flow. The left side of the general force-free jet/wind equation (the "pulsar" equation) is separated into a rotating and a nonrotating term. The two equations with either term can be solved analytically, and the two solutions match each other very well. Therefore, we obtain a general approximate solution of a magnetically dominated jet/wind, which covers from the nonrelativistic to relativistic regimes, with the drift velocity well matching the cold plasma velocity. The acceleration of a jet includes three stages. (1) The jet fl…

2021-01-14astro-ph.GAastro-ph.HEastro-ph.SR