eCite Digital Repository

The Nearest GHz Peaked Spectrum Radio Galaxy, PKS 1718-649


Tingay, SJ and Jauncey, DL and Reynolds, JE and Tzioumis, AK and King, EA and Preston, RA and Lovell, JEJ and McCulloch, PM and Costa, ME and Nicolson, G and Koekemoer, A and Tornikoski, M and Kedziora-Chudczer, L and Campbell-Wilson, D, The Nearest GHz Peaked Spectrum Radio Galaxy, PKS 1718-649, The Astronomical Journal, 113, (6) pp. 2025-2030. ISSN 0004-6256 (1997) [Refereed Article]

DOI: doi:10.1086/118414


In this paper we identify PKS 1718-649, at a distance of 56 Mpc (z=0.014; H0=75 km s-1 Mpc-1, q0=O), as the nearest GHz peaked-spectrum (GPS) radio galaxy, more than four times closer than any previously known. Extensive observations at radio wavelengths with the Australia Telescope Compact Array, the Southern Hemisphere VLBI Experiment array, and the Swedish-ESO Submillimetre Telescope have allowed us to determine the properties of the radio source: PKS 1718-649 consists of two compact sub-pc-scale components separated by approximately 2 pc, the overall radio polarization is low, and the radio spectrum is peaked near 3 GHz. Order-of-magnitude agreement between the quantitative model for GPS sources of Bicknell et al. [ApJ (1997) (in press)] and the radio data we present, as well as data at optical wavelengths from the literature, raises the interesting possibility that PKS 1718-649 may be frustrated in its development by the nuclear environment of its host galaxy, NGC 6328. The model of Bicknell et al. (1997) suggests free-free absorption as an explanation of the PKS 1718-649 radio spectrum. However, both free-free absorption and synchrotron self-absorption mechanisms are plausible for this source and both may contribute to the overall radio spectrum. PKS 1718-649 provides evidence to strengthen the speculative suggestion that GPS sources arise as a consequence of galaxy merger activity. © 1997 American Astronomical Society.

Item Details

Item Type:Refereed Article
Research Division:Physical Sciences
Research Group:Astronomical sciences
Research Field:Galactic astronomy
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the physical sciences
UTAS Author:Lovell, JEJ (Dr Jim Lovell)
UTAS Author:McCulloch, PM (Professor Peter McCulloch)
UTAS Author:Costa, ME (Dr Marco Costa)
ID Code:10103
Year Published:1997
Web of Science® Times Cited:38
Deposited By:Physics
Deposited On:1997-08-01
Last Modified:2011-08-11

Repository Staff Only: item control page