We present numerical simulations of axisymmetric, magnetically driven relativistic jets. Our special-relativistic, ideal-magnetohydrodynamics scheme is specifically designed to optimize accuracy and resolution minimize dissipation. In addition, we implement a grid-extension method that reduces the computation time by up three orders magnitude makes it possible follow flow six decades in spatial scale. To eliminate dissipative effects induced free boundary with an ambient medium assume...

We present a relativistic-MHD numerical study of axisymmetric, magnetically driven jets with parameters applicable to gamma-ray burst (GRB) flows. also analytic expressions for the asymptotic jet shape and other flow that agree very well results. All current-carrying outflows exhibit self-collimation consequent acceleration near rotation axis, but unconfined lose causal connectivity across therefore do not collimate or accelerate efficiently in their outer regions. Magnetically accelerated...

The basic properties of relativistic magnetohydrodynamics, as a hyperbolic system quasi-linear conservation laws, are discussed. These then used to develop multidimensional Godunov-type numerical scheme that enforces the magnetic flux conservation. This is based on linear Riemann solvers and has second-order accuracy in smooth regions. results thorough test calculations demonstrate robust can cope with truly ultrarelativistic problems.

The main goal of this research is to get better insights into the properties plasma-filled magnetospheres black holes by means direct numerical simulations and, ultimately, resolve controversy surrounding Blandford–Znajek mechanism. Driven need write equations hole electrodynamics in a form convenient for applications, we constructed new system 3 + 1 equations, which not only has more traditional than now classic Thorne and Macdonald but also general. To deal with magnetospheric current...

In this paper, we give a detailed description of the first attempt to study properties flow produced by magnetized pulsar wind within plerionic nebula via fully relativistic magnetohydrodynamic (MHD) simulations. Following current theoretical models winds, assume that in equatorial direction magnetization drops zero but its energy flux reaches maximum. The results our 2D axisymmetric simulations reveal complex dynamics post-shock flow, very different from steady quasi-radial outflow assumed...

In this paper we give a detailed account of the first three-dimensional (3D) relativistic magnetohydrodynamic (MHD) simulations Pulsar Wind Nebulae (PWN), with parameters most suitable for Crab Nebula.In order to clarify new features specific 3D models, reference 2D have been carried out as well.Compared previous simulations, considered pulsar winds much stronger magnetisation, up σ few, and accounted more accurately anticipated magnetic dissipation in striped zone these winds.While models...

In this paper we present the results of time-dependent simulations dipolar axisymmetric magnetospheres neutron stars carried out both within framework relativistic magnetohydrodynamics and resistive force-free electrodynamics. The reveal inability our numerical method to accommodate equatorial current sheets pulsar raise a question mark over robustness approach. On other hand, MHD approach allows make significant progress. We start with nonrotating magnetically dominated follow its evolution...

The strong variability of magnetic central engines active galactic nuclei (AGNs) and gamma-ray bursts (GRBs) may result in highly intermittent strongly magnetized relativistic outflows. We find a new acceleration mechanism for such impulsive flows that can be much more effective than the steady-state flows. This results kinetic-energy-dominated are conducive to efficient dissipation at internal magnetohydrodynamic shocks on astrophysically relevant distances from source. For spherical flow,...

In stark contrast to their laboratory and terrestrial counterparts, cosmic jets appear be very stable. They are able penetrate vast spaces, which exceed by up a billion times the size of central engines. We propose that reason behind this remarkable property is loss causal connectivity across these jets, caused rapid expansion in response fast decline external pressure with distance from 'jet engine'. atmospheres power-law distribution, pext ∝ z−κ, total occurs, when κ > 2 – steepness...

The time-dependent general relativistic equations of degenerate electrodynamics are solved numerically in order to study the mechanism electromagnetic extraction rotational energy black holes. We performed a series 2D runs for holes with specific angular momentum, a, from 0.1 0.9 and monopole magnetic field assuming axisymmetry. In inner region wind, solution quickly settles steady state an outgoing Poynting flux. all cases velocity lines is almost half hole. Thus, at least configuration...

In this paper we report the results of axisymmetric relativistic magnetohydrodynamic (MHD) simulations for problem a Kerr black hole immersed in rarefied plasma with 'uniform' magnetic field. The long-term solution shows properties that are significantly different from those initial transient phase studied recently by Koide. topology field lines within ergosphere is similar to split-monopole model strong current sheet equatorial plane. Closer inspection reveals system isolated islands inside...

This paper formulates time-dependent, force-free, degenerate electrodynamics as a hyperbolic system of conservations laws. It is shown that this has four characteristic modes, pair fast waves propagating with the speed light and Alfvén waves. All these modes are linearly degenerate. The results analytic study can be used in developing upwind numerical schemes for black hole pulsar magnetospheres. As an example, describes simple one-dimensional scheme based on linear exact Riemann solvers.

VLA maps of total intensity and fractional polarization at λ3.6 cm are presented for 11 radio galaxies, part a sample 29 nearby galaxies with P178 > 1.5 × 1025 W Hz−1 sr−1. Ten have classical double structure. The hotspots in all these well resolved. We discovered one-sided jet 3C 135, as imaging the known jets 98, 111 445 high resolution. There also possible five remaining six doubles. eleventh object, 15, is imaged here first time. It dominated by bright jet, weak counterjet detected.

The large-scale flow produced by classical and relativistic jets in a uniform external medium is explored using combination of general arguments numerical simulations. We find that both cases, with finite initial opening angles are recollimated the high pressure cocoon outer becomes approximately self-similar at large times. However, if angle significantly less than 20°, then there an intermediate stage during which working surface propagates constant speed, same order as jet. behaviour very...

In this paper we report the results of first ever time-dependent general relativistic magnetohydrodynamic simulations magnetically dominated monopole magnetospheres black holes. It is found that numerical solution evolves towards a stable steady-state which very close to corresponding force-free by Blandford and Znajek. Contrary recent claims, particle inertia does not become dynamically important near event horizon approximation provides proper framework for For time, our show development...

The stars of the parent galaxies inject matter into extragalactic jets in form stellar winds. From present-day estimated mean mass-loss rate by ellipticals, |$\dot{M}$| = 10–12 M⊙ yr–1, we can infer that mass injected is high enough to slow weak FR-1 radio sources down subrelativistic velocities, but not FR-II jets. This deceleration overcomes apparent contradiction between unification scheme for FR-Is and BL Lacs low velocities FR-I at kiloparsec scales. In this paper interaction a...

The expulsion of axisymmetric magnetic field from the event horizons rapidly rotating black holes has been seen as an astrophysically important effect that may significantly reduce or even nullify efficiency Blandford-Znajek mechanism powering relativistic jets in Active Galactic Nuclei and Gamma Ray Bursts. However, this Meissner-like is vacuum solutions hole electrodynamics whereas concerned with plasma-filled magnetospheres. In paper we argue conductivity dramatically changes properties...

The dynamics of accretion discs around galactic and extragalactic black holes may be influenced by their magnetic field. In this paper we generalise the fully relativistic theory stationary axisymmetric tori in Kerr metric Abramowicz et al.(1978) including strong toroidal field construct analytic solutions for barotropic with constant angular momentum. This development is particularly important general computational magnetohydrodynamics that suffers from lack exact are needed to test computer codes.

In this letter, we describe results of new high-resolution axisymmetric relativistic MHD simulations Pulsar Wind Nebulae. The reveal strong breakdown the equatorial symmetry and highly variable structure pulsar wind termination shock. synthetic synchrotron maps, constructed using a more accurate approach, show striking similarity with well known images Crab Nebula obtained by Chandra, Hubble Space Telescope. addition to jet-torus structure, these maps reproduce Crab's famous moving wisps...

We present first results of three dimensional relativistic magnetohydrodynamical simulations Pulsar Wind Nebulae. They show that the kink instability and magnetic dissipation inside these nebulae may be key processes allowing to reconcile their observations with theory pulsar winds. In particular, size termination shock, obtained in simulations, agrees very well even for Poynting-dominated Due total pressure simulated is particle-dominated more or less uniform. While main body field becomes...

The oblique geometry of pulsar wind termination shock ensures that the Doppler beaming has a strong impact on emission. We illustrate this using recent relativistic MHD simulations Crab Nebula and also show observed size, shape, distance from inner knot are consistent with its interpretation as Doppler-boosted emission shock. If electrons responsible for synchrotron gamma-rays accelerated only at then their short life-time these originate close to strongly effected by beaming. As result,...

In this paper, we discuss the development of Rayleigh–Taylor (RT) filaments in axisymmetric simulations pulsar wind nebulae (PWN). High-resolution adaptive mesh refinement magnetohydrodynamic are used to resolve non-linear evolution instability. The typical separation is mediated by turbulent flow nebula and hierarchical growth filaments. strong magnetic dissipation field randomization found recent global three-dimensional PWN suggest that tension not enough suppress RT filaments, agreement...

When astrophysical jets were discovered one hundred years ago, the field of numerical simulations did not yet exit. Since arrival programmable computers though, have increasingly become an indispensable tool for dealing with "tough nut" problems which involve complex dynamic and non-linear phenomena. Astrophysical are ideal example such a tough nut, where multi-scale plasma physics, radiative non-thermal processes, turbulence relativity combine to present formidable challenge researchers....

Superluminal motions observed in very long-baseline interferometry (VLBI) radio sources are generally believed to be associated with moving shocks a collimated relativistic flow. Recent progress numerical fluid dynamics now makes it possible carry out simulations of such flows. In this paper we calculate the flow that occurs when shock caused by source variability encounters reconfinement induced pressure gradient medium through which jet propagates. We then use radiative transfer equation...

The propagation of light highly relativistic jets carrying a toroidal magnetic field is studied numerically. results show that with high Poynting flux develop the conspicuous nose cones discovered earlier in simulations classical magnetized jets. size cone significantly reduced kinetic energy-dominated jets, which extensive cocoons. nevertheless plays significant role jet-cocoon dynamics by allowing self-confined flows. are explained terms properties perpendicular magnetohydrodynamic shocks.