相关论文: Magnetic fields in jets: ordered or disordered?

The magnetic field is believed to play a critical role in the bulk acceleration and propagation of jets produced in active galactic nuclei (AGN). Polarization observations of AGN jets provide valuable information about their magnetic…

Recently, evidence for synchrotron emission in both black hole and neutron star X-ray binaries has been mounting, from optical/infrared spectral, polarimetric, and fast timing signatures. The synchrotron emission of jets can be highly…

Motivated by recent observations that show increasing fractional linear polarization with increasing wavelength in a small number of optically thin jet features, i.e. "inverse depolarization", we present a physical model that can explain…

Evidence that the magnetic fields of extragalactic jets have a significant fraction of their energy in a random component is briefly summarized, and a detailed model of evolving, jet polarization structures is constructed, based on this…

Many quasars and active galactic nuclei (AGN) appear in radio, optical, and X-ray maps, as a bright nuclear sources from which emerge single or double long, thin jets (Thomson et al., 1993). When observed with high angular resolution these…

In inhomogeneous optically thick synchrotron sources a substantial part of the electron population at low energies can be hidden by self-absorption and overpowered by high energy electrons in optically thin emission. These invisible…

Synchrotron radiation is commonly observed in connection with shocks of different velocities, ranging from relativistic shocks associated with active galactic nuclei, gamma-ray bursts or microquasars to weakly- or non-relativistic flows as…

Relativistic magnetized jets are key elements in Active Galactic Nuclei and in other astrophysical environments. Their structure and evolution involves a complex nonlinear physics that can be approached by numerical studies only. Still,…

We describe a geometric model for synchrotron radiation from blazar jets, involving multiple emission zones with turbulent magnetic fields and a transient core with a helical B field. Including the effects of jet divergence, particle…

We present relativistic magnetohydrodynamic (RMHD) simulations of stationary overpressured magnetized relativistic jets which are characterized by their dominant type of energy, namely internal, kinetic, or magnetic. Each model is threaded…

The kinetic effects of magnetic fields on the transport of relativistic jet in the intergalactic medium remain uncertain, especially for their perpendicular component. By particle-in-cell simulations, we find that when only jet electrons…

Both in the Faraday Rotation Measure and the intrinsic polarization angle, new features are revealed to indicate a helical magnetic field operating along the jet of the bright active galactic nuclei 3C 273. The helical field has been…

We provide estimates for the flux and maximum frequency of radiation produced when the magnetic field in a relativistic, highly magnetized, jet is dissipated and particles are accelerated using general considerations. We also provide limits…

We present results from multifrequency polarimetry of NRAO 140 using the Very Long Baseline Array. These observations allow us to reveal the distributions of both the polarization position angle and the Faraday rotation measure (RM). These…

One of the tools that can provide evidence about the existence of helical magnetic fields in AGN is the observation of rotation measure gradients across the jet. Such observations have been previously made successfully, proving that such…

Multi-frequency (4.6, 5, 5.5, 8, 8.8, 13, 15, 22 & 43 GHz) polarization observations of 6 "blazars" were obtained on the American Very Long Baseline Array (VLBA) over a 24-hr period on 2 July 2006. Observing at several frequencies,…

Many quasars and active galactic nuclei (AGN) appear in radio, optical, and X-ray maps, as a bright nuclear sources from which emerge single or double long, thin jets. When observed with high angular resolution these jets show structure…

Recently it was shown that the centrifugal instability may be important in the dynamics of astrophysical jets undergoing reconfinement by external pressure. However, these studies were limited to the case of unmagnetised flows. Here we…

We investigate the effect of the jet's immediate surroundings on the non-thermal synchrotron emission and its polarization properties. The ambient medium is equipped with a turbulent magnetic field, which is compressed and amplified by the…

Two three-dimensional magnetohydrodynamical simulations of strongly magnetized conical jets, one with a poloidal and one with a helical magnetic field, have been performed. In the poloidal simulation a significant sheath (wind) of…