Sub-Milliarcsecond Imaging of Quasars and Active Galactic Nuclei. IV. Fine-Scale Structure

  title={Sub-Milliarcsecond Imaging of Quasars and Active Galactic Nuclei. IV. Fine-Scale Structure},
  author={Yuri Y. Kovalev and Kenneth I. Kellermann and Matthew L. Lister and Daniel C. Homan and Ren{\'e} C. Vermeulen and M. H. Cohen and Eduardo Ros and Matthias Kadler and Andrew P. Lobanov and J. Anton Zensus and N. S. Kardashev and L. I. Gurvits and Margo F. Aller and H. D. Aller},
  journal={The Astronomical Journal},
  pages={2473 - 2505}
We have examined the compact structure in 250 flat-spectrum extragalactic radio sources using interferometric fringe visibilities obtained with the Very Long Baseline Array (VLBA) at 15 GHz. With projected baselines out to 440 Mλ, we are able to investigate source structure on typical angular scales as small as 0.05 mas. This scale is similar to the resolution of the VLBI Space Observatory Programme data obtained on longer baselines at a lower frequency and with somewhat poorer accuracy. For… 
Compact Bright Radio-loud AGNs. III. A Large VLBA Survey at 43 GHz
We present the results from the 43 GHz Very Long Baseline Array (VLBA) observations of 124 compact radio-loud active galactic nuclei (AGNs) that were conducted between 2014 November and 2016 May. The
We present results from a large 86 GHz global very long baseline interferometry (VLBI) survey of compact radio sources. The main goal of the survey is to increase by factors of 3–5 the total number
The radio properties of blazars detected by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope have been observed contemporaneously by the Very Long Baseline Array (VLBA). In
We present Very Long Baseline Array (VLBA) images of 20 TeV blazars not previously well studied on the parsec scale. All 20 of these sources are high-frequency peaked BL Lac objects (HBLs).
The VSOP 5 GHz Active Galactic Nucleus Survey. III. Imaging Results for the First 102 Sources
The VLBI Space Observatory Programme (VSOP) mission is a Japanese-led project to study radio sources with sub-milliarcsec resolution using an orbiting 8 m telescope, HALCA, along with global arrays
VLBA observations of a rare multiple quasar imaging event caused by refraction in the interstellar medium
Aims. We have investigated highly atypical morphological parsec-scale changes in the flat spectrum extragalactic radio source 2023+335 which are coincident with an extreme scattering event (ESE) seen
The Most Compact Bright Radio-loud AGNs. II. VLBA Observations of 10 Sources at 43 and 86 GHz
Radio-loud active galactic nuclei (AGNs), hosting powerful relativistic jet outflows, provide an excellent laboratory for studying jet physics. Very long baseline interferometry (VLBI) enables
The Shroud Around the Twin Radio Jets in NGC 1052
We discuss multiple Very Long Baseline Interferometry (VLBI) continuum and spectral line imaging observations and Westerbork Synthesis Radio Telescope spectroscopy of the compact variable nuclear
Space VLBI Observations of 3C 279 at 1.6 and 5 GHz
We present VLBI Space Observatory Programme (VSOP) observations of the gamma-ray blazar 3C 279 at 1.6 and 5 GHz made on 1998 January 9-10 with the HALCA satellite and ground arrays including the Very
VLBA 24 and 43 GHz observations of massive binary black hole candidate PKS 1155 + 251
PKS 1155 + 251 is a radio-loud quasar source at z = 0.203. Observations using very long baseline interferometry (VLBI) at ∼2, 5, 8 and 15 GHz show that the structure of the radio source is quite


Very-long-baseline radio interferometry surveys of the compact structure in active galactic nuclei.
  • P. Wilkinson
  • Physics
    Proceedings of the National Academy of Sciences of the United States of America
  • 1995
Very-long-baseline radio interferometry (VLBI) imaging surveys have been undertaken since the late 1970s. The sample sizes were initially limited to a few tens of objects but the snapshot technique
VLA observations of a complete sample of core-dominated radio sources
Maps with high dynamic range are presented of a well-defined sample of powerful core-dominated radio sources, all of which have 5-GHz core flux densities >1 Jy. The maps were made at a frequency of
A multi-frequency VLBA polarization study of 3C 309.1
VLBA Imaging of NGC 4261: Symmetric Parsec-scale Jets and the Inner Accretion Region
We observed the nuclear region of NGC 4261 (3C 270) with VLBI to determine the morphology of the central radio source on parsec scales and in particular to see whether the inner radio axis remained
The EGRET detection of quasar 1633+382
In the course of a full-sky survey, the EGRET instrument aboard the Compton Observatory detected an intense, high Galactic latitude source, which is identified as the OVV (optically violent variable)
The VSOP 5 GHz Continuum Survey: The Prelaunch VLBA Observations
We have imaged with milliarcsecond resolution at 5 GHz 374 strong flat-spectrum radio sources north of declination -44° using the VLBA in 1996 June. The source sample was compiled from the source
The VSOP 5 GHz AGN Survey I. Compilation and Observations
The VSOP mission is a Japanese-led project to image radio sources with sub-milliarcsec resolution by correlating the signal from the orbiting 8-m telescope, HALCA, with a global array of telescopes.
VLBI and Merlin observations of 3C 120 at 1. 7 GHz - superluminal motions beyond 0. 05 arcsec
The radio galaxy 3C 120 was observed at 1.7 GHz in 1982 and 1984 with VLBI arrays, and the results are reported. Significant changes in the radio structure are seen on scales out to 100 mas between
Survey of instantaneous 1-22 GHz spectra of 550 compact extragalactic objects with declinations from -30 deg to +43 deg
We present observational results for extra- galactic radio sources with milliarcsecond components, obtained with the 600 meter ring radio telescope RATAN{600 from 1st to 22nd December, 1997. For each
PKS 0405–385: The Smallest Radio Quasar?
We have observed profound variability in the radio flux density of the quasar PKS 0405-385 on timescales of less than an hour; this is unprecedented among extragalactic sources. If intrinsic to the