Related papers: Microarcsecond structure of an AGN Jet via Interst…
We present for the first time Very-Long-Baseline Interferometry images of the radio galaxy Cygnus A at the frequency of $86$ $\rm GHz$. Thanks to the high spatial resolution of only ${\sim}200$ Schwarzschild radii ($R_{\bf S}$), such…
To investigate the connection between radio activity and AGN outflows, we present a study of ionized gas kinematics based on [O III] $\lambda$5007 emission line along the large-scale radio jet for six radio AGNs. These AGNs are selected…
There is theoretical and observational evidence that the jet core position changes with frequency. However, the core position for a given frequency may vary with time in the case of flares or for a precessing jet. In this work, we want to…
Outflows accelerated by AGN are commonly observed in the form of coherent, mildly collimated high-velocity gas directed along the AGN ionisation cones and kinetically powerful (>$10^{44-45}$ erg/s) jets. Recent works found that outflows can…
We monitored the M87 jet with the ACIS-S detector on Chandra with 5 observations between 2002 Jan and 2002 Jul. Our goal was to determine the presence and degree of variability in morphology, intensity, and spectral parameters. We find…
Imaging X-ray spectroscopy of nearby AGNs, mostly with Chandra, has shown that extended soft (<2.5 keV) emission-line dominated X-ray biconical structures, of kiloparsec scale, are widespread in highly absorbed Compton Thick (CT) AGNs. The…
AGN jets carry more than sufficient energy to stave off catastrophic cooling of the intracluster medium (ICM) in the cores of cool-core clusters. However, in order to prevent catastrophic cooling, the ICM must be heated in a near-isotropic…
The high-redshift quasar PMN J0909+0354 ($z=3.288$) is known to have a pc-scale compact jet structure, based on global 5-GHz very long baseline interferometry (VLBI) observations performed in 1992. Its kpc-scale structure was studied with…
For understanding the diversity of jetted active galactic nuclei (AGN) and especially the puzzling wide range in their radio-loudness, it is important to understand what role the magnetic fields play in setting the power of relativistic…
Our previous studies revealed a good kinematic model for the jet of Cygnus A, but the counter-jet speed is still not well constrained. The central engine and part of the counter-jet of Cyg A are likely to be obscured by free-free absorbing…
We present a detailed VLBI study of the spectral properties of the inner core region of the radio galaxy Cygnus A at 5 GHz, 15 GHz, 22 GHz, 43 GHz and 86 GHz. Our observations include an epoch using phase-referencing at 15 GHz and 22 GHz…
We present new more sensitive high-resolution radio observations of a compact broad absorption line (BAL) quasar, 1045+352, made with the EVN+MERLIN at 5 GHz. They allowed us to trace the connection between the arcsecond structure and the…
Observations of accreting black holes often provoke suggestions that their jets precess. The precession is usually supposed to result from a combination of the Lense-Thirring effect and accretion disc viscosity. We show that this is…
We propose that the knots of the large-scale jets in powerful radio sources represent moving and separate portions of the jet matter, with the excess kinetic power. This can explain many morphological properties of quasar jets - like high…
The jet activity of Active Galactic Nuclei (AGN), and its interaction with the interstellar medium (ISM), may play a pivotal role in the processes which regulate the growth and star formation of its host galaxy. Observational evidence which…
Observational studies of inner-most regions of the edge-on jets in nearby active galactic nuclei (AGN) are crucial to understand their kinematics and morphology. For the inner jet of the nearby low luminosity AGN in M 84, we present new…
We are investigating the kinematics of jets in active galactic nuclei on parsec scales by studying a representative population of sources. This study is being carried out using the Very Long Baseline Array at 15 GHz, with more than 800…
We propose that the X-ray emission detected by Chandra from the 100-kiloparsec-scale jet of PKS 0637-752 is produced through inverse Compton scattering of the Cosmic Microwave Background (CMB). We analyze the physical state of the jet and…
The recently discovered protostellar jet known as HH212 is beautifully symmetric, with a series of paired shock knots and bow shocks on either side of the exciting source region, IRAS 05413-0104 (Zinnecker et al. 1998). We present VLA…
The extreme, intra-hour and > 10% rms flux density scintillation observed in AGNs such as PKS 0405-385, J1819+3845 and PKS 1257-326 at cm wavelengths has been attributed to scattering in highly turbulent, nearby regions in the interstellar…