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We present multifrequency radio observations of two well known episodicFR\,II radio galaxies (J0116$-$4722 and J1158+2621) and a detailedinvestigation of the life-cycle of episodic radio galaxies from their spectraland radiative properties. Combining our previous work with the present results,we either constrain or place very good limits on the active and quiescentphases of a small sample of episodic FR\,II radio galaxies. The duration of thequiescent phase can be as small as the hotspot fading time of the previousepisode, and as high as a few tens of Myr; however, for none of the sources inour sample is it close to the duration of the active phase of the previousepisode. We also find that for many episodic radio galaxies, the nucleus isvariable at radio wavelengths. For our small sample of 7 episodic radiogalaxies, we find 4 to have strongly variable cores, a much larger proportionthan is generally found in samples of normal FR\,II radio galaxies. Studieswith larger samples will be required to establish a statistical associationbetween core variability and episodic radio activity.

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