Kenneth I. Kellermann

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We present 1625 new 15 GHz (2 cm) VLBA images of 295 jets associated with active galactic nuclei (AGNs) from the MOJAVE and 2 cm VLBA surveys, spanning observations between 1994 August 31 and 2013 August 20. For 274 AGNs with at least 5 VLBA epochs, we have analyzed the kinematics of 961 individual bright features in their parsec-scale jets. A total of 122(More)
We have used the Very Long Baseline Array at 15 GHz to image the structure of 132 strong compact active galactic nuclei (AGNs) and quasars with a resolution better than 1 mas and a dynamic range typically exceeding 1000 :1. These observations were made as part of a program to investigate the subparsec structure of quasars and AGNs and to study the changes(More)
The Very Long Baseline Array is a high-resolution synthesis radio telescope consisting of ten antennas, each 25 meters in diameter, located throughout the United States from Puerto Rico to Hawaii. Each antenna will be equipped with low-noise receivers spaced throughout the frequency range from 330 megahertz to 43 gigahertz, a hydrogen-maser frequency(More)
We report new 2 cm VLBA images of the inner radio jet of M87 showing a limb-brightened structure and unambiguous evidence for a faint 3 mas long counterfeature which also appears limb brightened. Multiepoch observations of seven separate jet features show typical speeds of less than a few percent of the speed of light, despite the highly asymmetric jet(More)
  • N. S. Kardashev, V. V. Khartov, +54 authors B. B. Kreisman
  • 2013
The Russian Academy of Sciences and Federal Space Agency, together with the participation of many international organizations, worked toward the launch of the RadioAstron orbiting space observatory with its onboard 10-m reflector radio telescope from the Baikonur cosmodrome on July 18, 2011. Together with some of the largest ground-based radio telescopes(More)
High resolution radio observations remain the most direct way to study the formation and evolution of radio jets associated with the accretion onto massive black holes. We report preliminary results of our seven year VLBA observational program to understand the nature of relativistic beaming in blazars and the surrounding environment of massive black holes.(More)
We report a change in the trajectory of a well studied jet component of the quasar 3C 279. The component changes in apparent projected speed and direction, and we find it to be moving with a Lorentz factor γ & 15 at an initial angle of . 1◦ to the line of sight. The new trajectory of the component has approximately the same speed and direction as an earlier(More)
We present deep, wide-field European VLBI Network (EVN) 1.6 GHz observations of the Hubble Deep Field (HDF) region with a resolution of 0.025 arcseconds. Above the 210 μJy/beam (5σ) detection level, the EVN clearly detects two radio sources in a field that encompasses the HDF and part of the Hubble Flanking Fields (HFF). The sources detected are: VLA(More)