We present the discovery of an active galactic nucleus (AGN) that is turningoff and then on again in the z=0.06 galaxy SDSS J1354+1327. This episodicnuclear activity is the result of discrete accretion events, which could havebeen triggered by a past interaction with the companion galaxy that iscurrently located 12.5 kpc away. We originally targeted SDSS J1354+1327 becauseits Sloan Digital Sky Survey spectrum has narrow AGN emission lines thatexhibit a velocity offset of 69 km s$^{-1}$ relative to systemic. To determinethe nature of the galaxy and its velocity-offset emission lines, we observedSDSS J1354+1327 with Chandra/ACIS, Hubble Space Telescope/Wide Field Camera 3,Apache Point Observatory optical longslit spectroscopy, and Keck/OSIRISintegral-field spectroscopy. We find a ~10 kpc cone of photoionized gas southof the galaxy center and a ~1 kpc semi-spherical front of shocked gas, which isresponsible for the velocity offset in the emission lines, north of the galaxycenter. We interpret these two outflows as the result of two separate AGNaccretion events; the first AGN outburst created the southern outflow, and then$<10^5$ yrs later the second AGN outburst launched the northern shock front.SDSS J1354+1327 is the galaxy with the strongest evidence for an AGN that hasturned off and then on again, and it fits into the broader context of AGNflickering that includes observations of AGN light echoes.

We present our recent results about the extended narrow-line region (ENLR) oftwo nearby Seyfert 2 galaxies (IC 5063 and NGC 7212) obtained by modelling theobserved line profiles and spectra with composite models(photoionization+shocks) in the different regions surrounding the AGN. Then, wecompare the Seyfert 2 ENLRs with the very extended one recently discovered inthe narrow-line Seyfert 1 (NLS1) galaxy Mrk 783. We have found severalevidences of interaction between the ISM of the galaxies and their radio jets,such as a) the contribution of shocks in ionizing the high velocity gas, b) thecomplex kinematics showed by the profile of the emission lines, c) the highfragmentation of matter, etc. The results suggest that the ENLR of IC 5063 havea hollow bi-conical shape, with one edge aligned to the galaxy disk, which maycause some kind of dependence on velocity of the ionization parameter.Regarding the Mrk 783 properties, it is found that the extension of the opticalemission is almost twice the size of the radio one and it seems due to the AGNactivity, although there is contamination by star formation around 12 arcsecfrom the nucleus. Diagnostic diagrams excluded the contribution of starformation in IC 5063 and NGC 7212, while the shock contribution was used toexplain the spectra emitted by their high velocity gas.