Super-luminal expansion in extragalactic radio sources

  title={Super-luminal expansion in extragalactic radio sources},
  author={Roger D. Blandford and Christopher F. McKee and Martin J. Rees},
Very long baseline (VLB) investigations of compact extragalactic radio sources can often be interpreted in terms of two non-thermal components apparently separating with speeds in excess of the speed of light. Given the conventional physical laws and the cosmological interpretation of large redshifts, the available morphological evidence, while inconclusive, is most compatible with a general class of models in which a signal propagating with a speed close to that of light is scattered by an… 
Large-scale radio structures of superluminal sources
Westerbork Synthesis Radio Telescope maps of faint extended emission associated with several superluminal radio sources are presented. In order to avoid exceptionally large sizes for the superluminal
Statistics of Superluminal Motion in Active Galactic Nuclei
We have collected an up-to-date sample of 123 superluminal sources (84 quasars, 27 BL Lac objects and 12 galaxies) and calculated the apparent velocities (βapp) for 224 components in the sources with
Extended and Compact Extragalactic Radio Sources: Interpretation and Theory
The interpretation of strong double radio sources in terms of the "beam" model is reviewed. Implications of this model for source evolution and the nature of radio trails are briefly discussed. A
Non-constant Superluminal Velocities in AGN
  • C. Coleman
  • Physics
    Publications of the Astronomical Society of Australia
  • 1990
Abstract Large apparent superluminal velocities are observed in nuclear jets in Active Galaxies, indicating the presence of relativistic velocities almost along the line of sight. If the flow is well
A possible interpretation of “superluminal” motions in radio galaxies
It was shown in an earlier paper (Gorbatskii, 1981) that jet-like ejections from the active nuclei of radio galaxies can be created by ejectors of relativistic electrons moving away from the nucleus.
Observations of galactic and extragalactic jets
Since nearly all discrete radio sources of astronomical interest are of insufficient angular extent for their detailed structural properties to be accessible to singledish radio telescopes, radio
Apparent superluminal expansion velocities in the dipole magnetic field model
VERY long baseline interferometry (VLBI) observations of compact radio sources have shown that the components of some radio sources seem to move apart with relative velocities more than twice the
Hubble's constant determined from super-luminal radio sources
Recent data on the so-called super-light expansion velocities observed in the radio galaxy 3C120 show a good fit to the light echo theory, provided the Hubble constant is 110 ± 10 km s−1 Mpc−1.
Superluminal quasar 3C179 with double radio lobes
VLBI observations of the quasar 3C179 reveal that its two milli arc second components have an apparent relative velocity of 7.6 times the velocity of light. This is the fifth radio source in which
Prominent VLBI cores in powerful radio sources with arc second structure
VLBI and aperture-synthesis techniques have produced better understanding of the structural details of extragalactic radio sources of both compact (<1 arc s) and extended (>10 arc s) types. Much less


A model for superlight velocities of extragalactic radio sources
An explanation is proposed for apparent superlight velocities of compact radio sources. In our model high velocities are a consequence of the interaction of the radio sources with the ambient gas in
In this paper, I will describe some recent results from high-resolution radio interferometry of extragalactic sources. I shall first, however, comment on the extraordinary range of important sizes in
Evidence for spatially independent outbursts in compact radio sources.
Observations of the 7.8-GHz flux-density variations of 3C 120 suggest that the apparent superrelativistic expansion of this source and others can be explained as being due to independent spatially
Apparent 'superrelativistic' expansion of the extragalactic radio source 3C 345
The compact extragalactic radio source 3C 345 was observed by very-long-baseline interferometry (wavelength about 3.8 cm) at 12 epochs distributed over the nearly four-year period from February 1971
Rapid increase in the size of 3C 345
The brightness distribution of the quasar 3C 345 at lambda=2.8 cm is accurately modeled with two Gaussian elliptical components. Observations at four epochs between 1974.15 and 1975.68 show that the
Observations of compact radio nuclei in Cygnus A, Centaurus A, and other extended radio sources
Observations of Cygnus A show a compact radio core 2 milliarcsec in extent oriented in the same direction as the extended components. Other large double- or multiple-component sources, including
One of the most controversial questions in radio astronomy at the present time is the interpretation of the velocities apparently faster than the speed of light observed at radio wavelengths in some
The spectrum and polarization of a source of synchrotron emission with components flying apart at relativistic velocities
In the present paper we consider the frequency spectrum, time variations and polarization of the flux of synchrotron radio emission from a source which consists of two components flying apart in
Accretion of matter by condensed objects
The equations of motion for steady-state spherical symmetric flow of matter into or out of a condensed object (e.g. neutron stars, ‘black holes’, etc.) are displayed and solved for simple polytropic
Synchrotron sources. I - Extension of theory for small pitch angles.
Some of the features of synchrotron radiation are examined which occur when relativistic particles move at small pitch angles in a magnetic field. The emission from individual particles is computed.