R. Gough

Publications (4)10.06 Total impact

• Article: VLBI Observations of Southern EGRET Identifications

  S. J. Tingay, P. G. Edwards, M. E. Costa, J. E. J. Lovell, P. M. McCulloch, D. L. Jauncey, J. E. Reynolds, A. K. Tzioumis, V. Migenes, R. Gough
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  ABSTRACT: We present high-resolution very long baseline interferometry images of three southern radio sources that the Energetic Gamma-Ray Experiment Telescope (EGRET), on board the Compton Gamma Ray Observatory, has identified as greater than 100 MeV gamma-ray sources. These are the first results in a continuing program of VLBI observations of southern EGRET identifications. For two of these sources, PKS 0208-512 (at 4.851 GHz) and PKS 0537-441 (at 4.851 and 8.418 GHz), the images represent first-epoch observations. For the remaining lower redshift object, PKS 0521-365, we present images from three epochs at 4.851 GHz and an image from one further epoch at 8.418 GHz, spanning approximately 1 yr. We discuss the need for further extensive VLBI observations of EGRET-identified radio sources.
  07/1996;
• Source

  Available from: adsabs.harvard.edu

  Article: VLBI Observations of Southern EGRET Identifications. I. PKS 0208-512, PKS 0521-365, and PKS 0537-441

  S. J. Tingay, P. G. Edwards, M. E. Costa, J. E. J. Lovell, P. M. McCulloch, D. L. Jauncey, J. E. Reynolds, A. K. Tzioumis, V. Migenes, R. Gough, [......], D. L. Jones, R. A. Preston, D. W. Murphy, D. L. Meier, T. D. van Ommen, M. St. John, D. W. Hoard, G. D. Nicolson, T.-S. Wan, Z.-Q. Shen
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  ABSTRACT: We present high-resolution very long baseline interferometry images of three southern radio sources that the Energetic Gamma-Ray Experiment Telescope (EGRET), on board the Compton Gamma Ray Observatory, has identified as greater than 100 MeV gamma-ray sources. These are the first results in a continuing program of VLBI observations of southern EGRET identifications. For two of these sources, PKS 0208-512 (at 4.851 GHz) and PKS 0537-441 (at 4.851 and 8.418 GHz), the images represent first- epoch observations. For the remaining lower redshift object, PKS 0521- 365, we present images from three epochs at 4.851 GHz and an image from one further epoch at 8.418 GHz, spanning approximately 1 yr. We discuss the need for further extensive VLBI observations of EGRET-identified radio sources.
  The Astrophysical Journal 05/1996; 464:170. · 6.02 Impact Factor
• Source

  Available from: articles.adsabs.harvard.edu

  Article: Parsec-Scale Morphology of PKS 2152-699 and the Radio/Optical Misalignment

  S. J. Tingay, D. L. Jauncey, J. E. Reynolds, A. K. Tzioumis, V. Migenes, R. Gough, J. E. J. Lovell, P. M. McCulloch, M. E. Costa, R. A. Preston, P. Harbison
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  ABSTRACT: We present the first very-long-baseline interferometry (VLBI) image of the parsec-scale structure in the nearby (z = 0.0282) Fanaroff-Riley type II radio galaxy PKS 2152-699, revealing the core-jet morphology typical of compact radio sources. Tadhunter et al. [MNRAS, 235,403(1988)] have identified this object as one in which the radio axis and optical emission line features on the kiloparsec-scale appear to have an obvious connection but are somewhat misaligned. They interpret this relationship as most likely being due to an interaction between the radio jet and an extra-nuclear cloud of gas, the misalignment possibly caused by the deflection of the radio jet in the interaction. The VLBI observations presented here further strengthen the evidence for the interaction interpretation. The parsec-scale radio jet aligns strongly with optical emission line features, and not with the kiloparsec-scale radio structure. We explore a mechanism which could produce the misalignment and which is consistent with the interaction concept, namely oblique shocks in a relativistic jet. With a minimal model we find that reasonable values of the model parameters can provide the required misalignment over a wide range of initial conditions.
  The Astronomical Journal 01/1996; 111:718. · 4.03 Impact Factor
• Article: Relativistic motion in a nearby bright X-ray source

  S. J. Tingay, D. L. Jauncey, R. A. Preston, J. E. Reynolds, D. L. Meier, D. W. Murphy, A. K. Tzioumis, D. J. McKay, M. J. Kesteven, J. E. J. Lovell, D. Campbell-Wilson, S. P. Elllngsen, R. Gough, R. W. Hunstead, D. L. Jonos, P. M. McCulloch, V. Migenes, J. Quick, M. W. Sinclair, D. Smits