Related papers: Parsec-scale jet direction evolution in AGNs
A long-term variability study spanning a range of black hole mass systems, from microquasars hosting stellar-mass black holes to active galactic nuclei (AGNs) harboring supermassive black holes, provides new insights into the physics of…
Simulations of active galactic nuclei (AGN) jets have thus far been performed almost exclusively using grid-based codes. We present the first results from hydrodynamical tests of AGN jets, and their interaction with the intracluster medium…
8.4-GHZ radio imaging study of an optically selected sample of early type Seyfert galaxies; comparison of images taken at two epochs reveals possible variation in the nuclear radio flux density in five of them over a seven year period. It…
Supermassive black holes launch highly relativistic jets with velocities reaching Lorentz factors as high as $\Gamma>50$. How the jets accelerate to such high velocities and where along the jet do they reach terminal velocity are open…
Radio interferometric observations of Active Galactic Nuclei (AGN) jets reveal the significant linear polarization of their synchrotron radiation that changes with frequency due to the Faraday rotation. It is generally assumed that such…
We used 15 GHz multi-epoch Very Long Baseline Array (VLBA) polarization sensitive observations of 484 sources within a time interval 1996--2016 from the MOJAVE program, and also from the NRAO data archive. We have analyzed the linear…
The magnetic field plays a significant role in the phenomenon of highly collimated jets of active galactic nuclei (AGN). Relativistic effects prevent the direct reconstruction of the magnetic field direction as transverse to electric…
A detailed analysis of the evolution of the properties of core-jet systems within the VLBA Imaging and Polarimetry Survey (VIPS) is presented. We find a power-law relationship between jet intensity and width that suggests for the typical…
We present 15 GHz stacked VLBA images of 373 jets associated with active galactic nuclei (AGN) having at least five observing epochs within a 20 yr time interval 1994-2015 from the MOJAVE programme and/or its precursor, the 2 cm VLBA…
A key characteristic of many active galactic nuclei (AGN) is their variability, but its origin is poorly understood, especially in the radio domain. Williams et al. (2017) reported a ~50 per cent increase in peak flux density of the AGN in…
We investigate the origin of the parsec-scale radio emission from the changing-look active galactic nucleus (AGN) of Mrk 590, and examine whether the radio power has faded concurrently with the dramatic decrease in accretion rates observed…
We present two- and three-dimensional hydrodynamic simulations of $\sim$kpc-scale AGN jets with mean jet powers in the range $1-7\times10^{45}\,$erg~s$^{-1}$, in which the jet power varies (through variation of the Lorentz factor) according…
The orientation of radio jets relative to their host galaxies offers an interesting avenue for probing the connection between active galactic nuclei (AGN) and their surroundings. Several studies have also investigated the orientation of…
We analyze a sample of 58 multi-wavelength, Very Long Baseline Array observations of active galactic nuclei (AGN) to determine their scattering properties. Approximately 75% of the sample consists of AGN that exhibit centimeter-wavelength…
The variability of active galactic nuclei (AGN) has long held the promise of shedding light on their detailed structure, and possibly other astrophysical phenonema. Different emission mechanisms lead to different patterns of variability in…
A number of groups have recently been active in searching for gradients in the ob- served Faraday rotation measure (RM) across jets of Active Galactic Nuclei (AGNs) on various scales and estimating their reliability. Such RM structures…
We present simulations of relativistic jets propagating in a nonuniform medium. Specifically, we study the bending of jets propagating obliquely to the vector of the density-gradient. Our results are applied to the NGC 4258, where such a…
We probe the role that the directional asymmetry, between relativistic outflows and kilo-parsec scale jets, play in the acceleration of cosmic rays. For this reason we use two powerful, nearby Active Galactic Nuclei (AGNs). These radio…
Radio polarimetry is an invaluable tool to investigate the physical conditions and variability processes in active galactic nuclei (AGN) jets. However, detecting their linear and circular polarization properties is a challenging endeavor…
Several narrow-line Seyfert 1 galaxies (NLS1s) have now been detected in gamma rays, providing firm evidence that at least some of this class of active galactic nuclei (AGN) produce relativistic jets. The presence of jets in NLS1s is…