Astron. Astrophys. 332, 479-492 (1998)

PKS 1932-464: a jet-cloud interaction in a radio galaxy? ^*

M. Villar-Martín ¹, C. Tadhunter ¹, R. Morganti ^{2, 3}, N. Clark ⁴, N. Killeen ³ and D. Axon <sup>4

1</sup> Department of Physics, University of Sheffield, Sheffield S3 7RH, UK
² Istituto di Radioastronomia, Via Gobetti 101, I-40129 Bologna, Italy
³ CSIRO-ATNF, PO Box 76, Epping NSW 2121, Australia
⁴ Space Telescope Science Institute, 3700 San Martin Drive, Baltimore MD21218, USA

Received 12 November 1997 / Accepted 22 December 1997

Abstract

We present optical and radio images, and long-slit spectra of the radio galaxy PKS 1932-464 (z=0.230). Our main goal is to determine whether the observed properties of the extended emission line nebulosity in this object show evidence for interactions between the radio jet and the extended ionized gas, or whether they can be explained in terms of the illumination of the extended gas by the active nucleus. Although the data do not show compelling evidence for jet-cloud interactions, the existence of two well distinguished emitting line regions with very different kinematics and ionization levels suggests the presence of such interactions. The large-scale gas distribution is complex and suggests a gravitational interaction between the host galaxy of PKS 1932-464 and a nearby companion galaxy. The detection of a broad H emission line in the nuclear spectrum of the object provides evidence that this object is a broad line radio galaxy (BLRG) rather than a narrow line radio galaxy (NLRG) as previously supposed.

Key words: galaxies: individual: PKS 1932-464 galaxies: ISM galaxies: jets galaxies: active radio continuum: galaxies

* Based on observations collected at Anglo Australian Observatory, Australia

Send offprint requests to: M. Villar-Martin, Department of Physics, University of Sheffield, Sheffield S3 7RH, UK

SIMBAD Objects

Contents

• 1. Introduction
• 2. Observations
  • 2.1. Optical imaging
  • 2.2. Radio observations
  • 2.3. Long-slit spectroscopy
• 3. Analysis and results
  • 3.1. The optical morphology
  • 3.2. The radio structure
  • 3.3. Radio polarization
  • 3.4. The spatial distribution of the emission lines
  • 3.5. The line ratios and ionization gradient
  • 3.6. The kinematics
• 4. Discussion
  • 4.1. The optical morphology and the connection with the radio structures
  • 4.2. PKS 1932-464 and the high redshift radio galaxies
  • 4.3. The line ratios and the emission line mechanism
  • 4.4. The kinematics
• 5. PKS 1932-464: a jet-cloud interaction in a radio galaxy?
  • 5.1. Alternative possibilities
• 6. Summary and conclusions
• Acknowledgements
• References

© European Southern Observatory (ESO) 1998

Online publication: March 23, 1998
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