Episodic radio galaxies J0116-4722 and J1158+2621: Can we constrain the quiescent phase of nuclear activity?

C. Konar, M.J. Hardcastle, M. Jamrozy, J.H. Croston

Research output: Contribution to journalArticlepeer-review

29 Citations (Scopus)
24 Downloads (Pure)

Abstract

We present multifrequency radio observations of two well-known episodic Fanaroff-Railey type II (FR II) radio galaxies (J0116-4722 and J1158+2621) and a detailed investigation of the life cycle of episodic radio galaxies from their spectral and radiative properties. Combining our previous work with the present results, we either constrain or place very good limits on the active and quiescent phases of a small sample of episodic FR II radio galaxies. The duration of the quiescent phase can be as small as the hotspot fading time of the previous episode, and as high as a few tens of Myr; however, for none of the sources in our sample is it close to the duration of the active phase of the previous episode. We also find that for many episodic radio galaxies, the nucleus is variable at radio wavelengths. For our small sample of seven episodic radio galaxies, we find four to have strongly variable cores, a much larger proportion than is generally found in samples of normal FR II radio galaxies. Studies with larger samples will be required to establish a statistical association between core variability and episodic radio activity
Original languageEnglish
Pages (from-to)2137-2153
Number of pages17
JournalMonthly Notices of the Royal Astronomical Society
Volume430
Issue number3
Early online date14 Feb 2013
DOIs
Publication statusPublished - 11 Apr 2013

Fingerprint

Dive into the research topics of 'Episodic radio galaxies J0116-4722 and J1158+2621: Can we constrain the quiescent phase of nuclear activity?'. Together they form a unique fingerprint.

Cite this