Extended optical emission-line regions in X-ray selected AGN

Voorwerpjes (VPs) are a unique kind of AGN, characterized by the presence of very extended (tens of kpc) ionized clouds, that appear to be primarily ionized by a once-powerful quasar. In sharp contrast, the central engine currently hosts a very dim AGN. These "light echoes" are able to preserve the AGN luminosity history, suggesting that these AGN have faded 2–5 orders of magnitude within the past 104−5 years. We have examined a sample of hard X-ray selected AGNs that are VP candidates with VLT/MUSE observations. This sample has expanded our understanding of VPs: we find that their incidence is higher than previously thought. Among this sample we observe that a large fraction of the VPs are hosted in Sy 1 galaxies and thus we are able to obtain a glimpse into these source's past histories.