Related papers: A High-Frequency and Multi-Epoch VLBI Study of 3C …
We monitored 3C273 with VLBI at 15-86 GHz since 1990. We discuss component trajectories, opacity effects at the jet base, a rotating and perhaps precessing jet, and outburst-ejection relations from Gamma-ray to radio bands.
Multi-epoch Very Long Baseline Interferometry (VLBI) study of the sub-pc scale jet of 3C 84 is presented. We carried out 14-epoch VLBI observations during 2006-2009 with the Japanese VLBI Network (JVN) and the VLBI Exploration of Radio…
We report multi-epoch Very Long Baseline Interferometry (VLBI) study of the innermost jet of 3C 84. We carried out 14-epoch VLBI observations during 2006-2009 with the Japanese VLBI Network (JVN) and the VLBI Exploration of Radio Astrometry…
The results of VLBI observations of the quasar 3C273, obtained during a multi-frequency campaign in late 1992 in the radio, millimeter and X-ray bands are presented and discussed. The VLBI observations were made at 22 GHz with a Global…
The broad-line radio galaxy 3C 111 exhibited a major flux density outburst in 2007. Here, we present imaging and preliminary kinematic results of the jet, based on three millimetre-VLBI observations (86 GHz) using the Global Millimeter VLBI…
Flares in radio-loud AGN are thought to be associated with the injection of fresh plasma into the compact jet base. Such flares are usually strongest and appear earlier at shorter radio wavelengths. Hence, VLBI at mm-wavelengths is best…
The mechanism and the region of generation of variable continuum emission are poorly understood for radio-loud AGN because of a complexity of the nuclear region. High-resolution radio VLBI (very long baseline interferometry) observations…
We investigate the relationship between the variable gamma-ray emission and jet properties in the blazar 3C 279, by combining the Fermi/LAT data spanning a period of eight years with concurrent radio measurements made at multiple epochs…
We present the observational results of the Gamma-ray blazar, 3C 66A, at 2.3, 8.4, and 22 GHz at 4 epochs during 2004-05 with the VLBA. The resulting images show an overall core-jet structure extending roughly to the south with two…
We present a new approach to derive the observed properties of synchrotron outbursts in relativistic jets. The idea is to use the very well sampled submillimetre-to-radio long-term light curves of 3C 273 to extract the spectral and temporal…
Due to its powerful radiation over the entire electromagnetic spectrum and its radio jet activity, the blazar 3C273 offers the opportunity to study the physics of $\gamma$-ray emission from active galactic nuclei. Since a historically…
We present the analysis of the radio jet evolution of the radio galaxy 3C 120 during a period of prolonged gamma-ray activity detected by the Fermi satellite between December 2012 and October 2014. We find a clear connection between the…
We observed the blazar \object{0716+714} with the VLBA during its active state in 2003-2004. In this paper we discuss multi-frequency analysis of the inner jet (first 1 mas) kinematics. The unprecedentedly dense time sampling allows us to…
We present an analysis of new and old high frequency VLBI data collected during the last 10 years at 5--22 GHz. For the jet components in the mas-VLBI jet, two component identifications are possible. One of them with quasi-stationary…
We discuss the parsec-scale structural variability of the extragalactic jet 3C 111 related to a major radio flux density outburst in 2007. The data analyzed were taken within the scope of the MOJAVE, UMRAO, and F-GAMMA programs, which…
The flat-spectrum radio quasar 3C 345 has been showing gamma-ray activity since the mid-2000s along with activity across the electromagnetic spectrum. A gamma-ray burst in 2009 was successfully linked to relativistic outflow in 43 GHz VLBI…
We present results from very-long-baseline-interferometry (VLBI) observations of the nucleus in the lobe-dominated quasar 3C207. These observations were completed at 8.4 or 10.7 GHz (X-band) from 1981 to 2010, spanning 29 years. The nucleus…
We present a high-frequency very long baseline interferometry (VLBI) kinematical study of the BL Lac object S5 0716+714 over the time period of September 2008 to October 2010. The aim of the study is to investigate the relation of the jet…
We present a comprehensive 5-43 GHz VLBA study of the blazar 3C 273 initiated after an onset of a strong $\gamma$-ray flare in this source. We have analyzed the kinematics of new-born components, light curves, and position of the apparent…
The VLBI observations at 22 GHz and 43 GHz of the quasar 3C273 obtained during a multi-frequency campaign in late 1992 in the radio, millimetre and X-ray bands allow us to derive the components' angular sizes, their peak fluxes and turnover…