Related papers: On the M87 jet structure near the central engine
We present results from 43 GHz (VLBA, six epochs from 2012.2 to 2013.2) and 86 GHz (GMVA, one epoch in 2012.4) observations toward the basis of the jet in the TeV Blazar Mrk 501. The 43-GHz data analysis reveals a new feature located…
Motivated by the measured velocity profile of the M87 jet using the KVN and VERA Array (KaVA) by Park et al. indicating that the starting position of the jet acceleration is farther from the central engine of the jet than predicted in…
In recent years, the jet formation region in active galaxies has been imaged through mm-VLBI in few ideal targets, first and foremost M87. An important leap forward for understanding jet launching could be made by identifying a larger…
Observational studies of collimation in jets in active galactic nuclei (AGN) are a key to understanding their formation and acceleration processes. We have performed an automated search for jet shape transitions in a sample of 367 AGN using…
The analysis of the frequency dependence of the observed shift of the cores of relativistic jets in active galactic nuclei (AGN) allows us to evaluate the number density of the outflowing plasma n and, hence, the multiplicity parameter,…
We discuss the jet kinematics of a complete flux-density-limited sample of 135 radio-loud active galactic nuclei (AGN) resulting from a 13 year program to investigate the structure and evolution of parsec-scale jet phenomena. Our analysis…
The kinematics of jets in active galactic nuclei (QSOs, BL Lacs, Radio Galaxies and Empty Field objects) on parsec scales is being studied with Very Long Baseline Array observations at 15 GHz of a sample of more than 170 radio sources. More…
High-resolution millimeter wave very-long-baseline interferometry (mm-VLBI) is an ideal tool for probing the structure at the base of extragalactic jets in detail. The TeV blazar Mrk 501 is one of the best targets among BL Lac objects for…
Modelling of deep VLA images of the jets in FR I radio galaxies has allowed us to derive their three-dimensional distributions of velocity, emissivity and magnetic-field structure on kiloparsec scales. By combining our models of jet…
We present unprecedented high fidelity radio images of the M87 jet. We analyzed Jansky Very Large Array (VLA) broadband, full polarization, radio data from 4 to 18 GHz. The observations were taken with the most extended configuration (A…
The apparent position of jet base (core) in radio-loud active galactic nuclei changes with frequency because of synchrotron self-absorption. Studying this `core shift` effect enables us to reconstruct properties of the jet regions close to…
We present observations made with the VLA at 1.5 and 8.4 GHz of the nearby FRI radio galaxy 3C296. The most recent models of FRI radio galaxies suggest that substantial deceleration must take place in their jets, with strongly relativistic…
Many active galaxies harbor powerful relativistic jets, however, the detailed mechanisms of their formation and acceleration remain poorly understood. To investigate the area of jet acceleration and collimation with the highest available…
The idea that systematic Faraday Rotation gradients across the parsec-scale jets of AGNs can reveal the presence of helical magnetic (B) fields has been around since the early 1990s. These gradients are taken to be due to the systematic…
We report first-epoch circular polarization results for 133 active galactic nuclei in the MOJAVE program to monitor the structure and polarization of a flux limited sample of extra-galactic radio jets with the VLBA at 15 GHz. We found…
We report on the detailed radio status of the M87 jet during the Very-High-Energy (VHE) gamma-ray flaring event in April 2010, obtained from high-resolution, multi-frequency, phase-referencing VLBA observations. We especially focus on the…
A recent article on high-resolution 86 GHz observations with the Global Millimeter VLBI Array, the phased Atacama Large Millimeter/submillimeter Array, and the Greenland Telescope describes the detection of a limb-brightened cylindrical…
The active galactic nucleus (AGN) within M87, a giant elliptical galaxy, is responsible for one of the closest kiloparsec-scale relativistic jet to Earth. We unearthed unpublished M87 polarization maps taken with the Faint Object Camera…
Preliminary VLBA polarisation results on 6 ``blazars'' from 6.5-cm to 7-mm are presented here. Observing at several different wavelengths, separated by short and long intervals, enabled reliable information about the magnetic (B) field…
The nearby radio galaxy M87 offers a unique opportunity for exploring the connection between gamma-ray production and jet formation at an unprecedented linear resolution. However, the origin and location of the gamma-rays in this source is…