Extended radio emission detected around a sample of GHz Peaked Spectrum (GPS) radio sources is discussed. Evidence for extended emission which is related to the GPS source is found in 6 objects out of 33. Three objects are associated with quasars with core-jet pc-scale morphology, and three are identified with galaxies with symmetric (CSO) radio morphology.We conclude that the core-jet GPS quasars are likely to be beamed objects with a continuous supply of energy from the core to the kpc scale. It is also possible that low surface brightness extended radio emission is present in other GPS quasars but the emission is below our detection limit due to the high redshifts of the objects. On the other hand, the CSO/galaxies with extended large scale emission may be rejuvenated sources where the extended emission is the relic of previous activity. In general, the presence of large scale emission associated with GPS galaxies is uncommon, suggesting that in the context of the recurrent activity model, the time scale between subsequent bursts is in general longer than the radiative lifetime of the radio emission from the earlier activity (~10^8 yrs) (Refer to PDF file for exact formulas).

Publication Date



This is the pre-print of an article published by EDP Sciences. The final, published version is available here: https://doi.org/10.1051/0004-6361:20042226

Reproduced with permission from Astronomy & Astrophyics, © 2005 ESO

Also archived in: arXiv: astro-ph/0507499 v1 21 Jul 2005

Part of this work has been done during visits of C.S. at the Space Telescope Science Institute, Baltimore, under the STScI Collaborative Visitor Program. The VLA is operated by the U.S. National Radio Astronomy Observatory which is operated by Associated Universities, Inc., under cooperative agreement with the National Science Foundation. The Westerbork Synthesis Radio Telescope is operated by the Netherlands Foundation for Research in Astronomy (NFRA) which is financially supported by the Netherlands organization for scientific research (NWO) in the Hague. We have made use of the NASA/IPAC Extragalactic Database, operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. This research has made use of the United States Naval Observatory (USNO) Radio Reference Frame Image Database (RRFID).

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Document Type


Department, Program, or Center

School of Physics and Astronomy (COS)


RIT – Main Campus