Related papers: Resolving the jet in Cygnus A
We report the first observation of a transient relativistic jet from the canonical black hole candidate, Cygnus X-1, obtained with the Multi-Element Radio-Linked Interferometer Network (MERLIN). The jet was observed in only one of six…
Context: Few Active Galactic Nuclei (AGN) reveal a double sided jet system. However, these are crucial to understand basic physical properties of extragalactic jets. Aims: We address the questions whether jets in AGN are symmetric in…
VLBA and Global VLBI observations of M87 at 43 GHz, some new and some previously published, are used to study the structural evolution of the jet with a spatial resolution of under 100 Schwarzschild radii. The images, taken between 1999 and…
We model the observed size and brightness of the VLBA radio core of the jet in Cygnus X-1 to derive an expression for the jet power as a function of basic jet parameters. We apply this expression to recent constraints on the jet power from…
We report detailed studies of the X-ray emission from the kpc scale jet in the nearest active galaxy, Cen A. 41 compact sources were found within the jet, 13 of which were newly identified. We construct the luminosity function for the…
We present preliminary results from high resolution (~ 0.05") adaptive optics observations of Cygnus A. The images show a bi-conic structure strongly suggestive of an obscuring torus around a quasar nucleus. A bright (K'=18.5) point source…
Very Long Baseline Array images of the X-ray binary, Cygnus X-3, were obtained 2, 4 and 7 days after the peak of a 10 Jy flare on 4 February 1997. The first two images show a curved one-sided jet, the third a scatter-broadened disc,…
We report two simulations that have been carried out at the SX-5 at HLRS (Stuttgart). One simulation is axisymmetric and purely hydrodynamic, but with a resolution of 20 points per beam-radius (ppb). The bipolar jet is injected in the…
We present the first direct imaging of what may be the thick torus in the active galactic nucleus (AGN) of the archetype powerful radio galaxy Cygnus A, using the Jansky Very Large Array (VLA) at 18 GHz to 48 GHz, with a resolution down to…
M87 is one of the best available source for studying the AGN jet-launching region. To enrich our knowledge of this region, with quasi-simultaneous observations using VLBA at 22, 43 and 86 GHz, we capture the images of the radio jet in M87…
Jets have been detected in only a few symbiotic binaries to date, and CH Cyg is one of them. In 2001, a non-relativistic jet was detected in CH Cyg for the first time in X-rays. We carried out coordinated Chandra, HST, and VLA observations…
We study the collimation and acceleration of the jets in the nearby giant radio galaxy NGC 315, using multifrequency Very Long Baseline Array observations and archival High Sensitivity Array and Very Large Array data. We find that the jet…
We investigate the jet propagation and breakout from the stellar progenitor for gamma-ray burst (GRB) collapsars by performing two-dimensional relativistic hydrodynamic simulations and analytical modeling. We find that the jet opening angle…
With the increased sensitivity and resolution of radio interferometry the study of the collimation and acceleration region of jets in Active Galactic Nuclei (AGN) has come into focus within the last years. Whereas a large fraction of AGN…
We study the properties of ultracompact jets in several prominent radio sources (Cygnus A, 3C 309.1, 3C 345, 3C 395, 4C 39.25, and 1038+528 A), using the frequency dependence of observed position of the optically thick jet core. Frequency…
We have used the VLBA to produce a high dynamic range image of the nucleus of NGC 6251 at 1.6 GHz and snapshot images at 5.0, 8.4, and 15.3 GHz to search for emission from a parsec-scale counterjet. Previous VLBI images at 1.6 GHz have set…
We detail the spectral analysis of a 170 ks XRISM Resolve observation of the core of Cygnus A. The high spectral resolution of Resolve have enabled us to probe the inner accretion region of Cygnus A by analyzing the 6.4 keV Fe K$\alpha$…
Recent Chandra X-ray observations of jets in central cluster galaxies show interesting features around the symmetry plane. We have carried out simulations involving bipolar jets, removing the artificial boundary condition at the symmetry…
Understanding the launching, acceleration, and collimation of jets powered by active galactic nuclei remains an outstanding problem in relativistic astrophysics. This is partly because observational tests of jet formation models suffer from…
We present results of our detailed theoretical study of the observed orbital modulation of the radio emission in Cyg X-1. The modulation occurs due to free-free absorption in the wind from the companion star varying with the orbital phase,…