Related papers: Radio source evolution and the interplay with the …
VLBI observations of relativistic outflows (jets) in galactic nuclei, complemented with detailed studies made in other spectral domains, have become an effective tool for investigating the physics of nuclear regions in galaxies.…
Galaxies form out of small fluctuations in a smoothly expanding Universe. However, the initial gravitational collapse phase is accompanied by the formation of supermassive black holes and clusters of massive stars. Black holes and star…
Relativistic stellar jets, produced in binary systems called microquasars, propagate through media with different spatial scales releasing their energy in the form of work and radiation from radio to gamma rays. There are several…
We present a numerical investigation of dead, or relic, radio galaxies and the environmental impact that radio galaxy activity has on the host galaxy or galaxy cluster. We perform axisymmetric hydrodynamical calculations of light,…
Jets from young stars represent one of the most striking signposts of star formation. The phenomenon has been researched for over two decades and there is now general agreement that such jets are generated as a by-product of accretion; most…
Jets are observed to stir up multi-phase turbulence in the inter-stellar medium as well as far beyond the host galaxy. Here we present detailed simulations of this process. We evolve the hydrodynamics equations with optically thin cooling…
We investigate the evolution of a disk wind into a collimated jet under the influence of magnetic diffusivity, assuming that the turbulent pattern in the disk will also enter the disk corona and the jet. Using the ZEUS-3D code in the…
Stars with outflows interacting with ambient gas experience accelerations arising from the gravitational feedback induced by the interaction structure. In this work, three-dimensional (3D) local shearing box simulations are performed to…
Processes driven by unsteady reconnection can efficiently accelerate particles in many astrophysical plasmas. An example are the reconnection jet fronts in an outflow region. We present evidence of suprathermal ion acceleration between two…
The current understanding of the formation of powerful bi-directional jets in systems such as radio galaxies and quasars is that the process involves a supermassive black hole that is being fed with magnetized gas through an orbiting…
Ranging from a few pc to hundreds of kpc in size, radio jets have, during their evolution, an impact on their gaseous environment on a large range of scales. While their effect on larger scales is well established, it is now becoming clear…
Astrophysical jets are associated with the formation of young stars of all masses, stellar and massive black holes, and perhaps even with the formation of massive planets. Their role in the formation of planets, stars, and galaxies is…
A number of observations have revealed atomic and/or molecular lines in active galaxies hosting jets and outflows. Line widths indicate outward motions of hundreds to few thousands of kilometers per second. They appear associated to the…
We summarise the recent progress of a project to determine physical conditions in the jets of low-luminosity (FR I) radio galaxies. We model the jets as intrinsically symmetrical, relativistic, decelerating flows. By fitting to deep,…
Active galactic nuclei (AGN) show a range of morphologies and dynamical properties, which are determined not only by parameters intrinsic to the central engine but also their interaction with the surrounding environment. We investigate the…
We investigate the evolution of a disk wind into a collimated jet under the influence of magnetic diffusivity. Using the ZEUS-3D code in the axisymmetry option we solve the time-dependent resistive MHD equations for a model setup of a…
We present a 3D magnetohydrodynamic (MHD) study of narrow-angle tail (NAT) radio galaxy (RG) dynamics, including passive cosmic ray electrons. We follow evolution of a bipolar-jet RG in a persistent crosswind through hundreds of Myr. We…
High-resolution Very-Long-Baseline Interferometry observations of NGC 1052 show a two sided jet with several regions of enhanced emission and a clear emission gap between the two jets.This gap shrinks with increasing frequency and vanishes…
High-resolution Very-Long-Baseline Interferometry observations of active galactic nuclei have revealed asymmetric structures in the jets of radio galaxies. These asymmetric structures may be due to internal asymmetries in the jet, could be…
In the case of an initially conical jet, we study the relation between jet collimation by the external pressure and large-scale morphology. We first consider the important length-scales in the problem, and then carry out axisymmetric…