Speaker
Description
AGN are known to undergo multiple cycles of activity but the mechanisms behind these are still under debate. However, such details are crucial information for understanding galaxy evolution and the mechanisms driving jet triggering. We have used 250 to 850 MHz uGMRT (σ = 4 µJy/beam) and 1.4 GHz MeerKAT (σ = 1.5 µJy/beam) observations of the XMM-LSS field under the superMIGHTEE and MIGHTEE surveys, respectively, to select a parent sample of radio galaxies. From visual inspection of their morphology, we found eighteen potential restarted radio galaxies characterized by the so-called Double-Double Radio Galaxy (DDRG) structure. Where the source displays a double pair of lobes which have been proven to be an imprint of intermittency of their nuclear activity. By using other search criteria, such as a high core prominence and the core spectral properties, we found forty six restarted radio AGN in total and six from which were selected by two different criteria. This yields a fraction of seventeen percent of our parent sample. By using superMIGHTEE observations, we computed the spectral index map of the covered area. Then the visual inspection of the map allowed the discovery of a few additional restarted RG candidates. Furthermore, we made the discovery of the sixth known triple-double radio galaxy (TDRG). In regard to the context of DDRGs, TDRGs are believed to embody sources with three cycles of nuclear activity which is supported by the index distribution of this TDRG.
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