2019MNRAS.489.4049H

Mrk 1498 is part of a sample of galaxies with extended emission-line regions (extended outwards up to a distance of ∼7 kpc) suggested to be photoionized by an AGN that has faded away or that is still active but heavily absorbed. Interestingly, the nucleus of Mrk 1498 is at the centre of two giant radio lobes with a projected linear size of 1.1 Mpc. Our multiwavelength analysis reveals a complex nuclear structure, with a young radio source (Giga-hertz Peaked Spectrum) surrounded by a strong X-ray nuclear absorption, a mid-infrared spectrum that is dominated by the torus emission, plus a circumnuclear extended emission in the [O III] image (with radius of ∼1 kpc), most likely related to the ionization of the AGN, aligned with the small- and large-scale radio jet and extended also at X-rays. In addition a large-scale extended emission (up to ∼10 kpc) is only visible in [O III]. These data show conclusive evidence of a heavily absorbed nucleus and has recently restarted its nuclear activity. To explain its complexity, we propose that Mrk 1498 is the result of a merging event or secular processes, such as a minor interaction, that has triggered the nuclear activity and produced tidal streams. The large-scale extended emission that gives place to the actual morphology could either be explained by star formation or outflowing material from the AGN.