Extended ionized-gas structures in Seyfert 2 galaxy Mrk 78
  Search for and study of extended emission-line regions (EELRs) related to AGN
in early-type galaxies is interesting to probe the history of nuclear
ionization activity and also to understand the process of external gas
accretion. In this work, we present observations of the EELR in Mrk 78 obtained
at the 6-m Russian telescope using the long-slit and 3D spectroscopy methods.
We show that ionized-gas clouds at the 12-16 kpc projected distances from the
nucleus are ionized by the AGN radiation. Also we have checked if the galaxy
appearing in the optical images in the immediate neighbourhood of Mrk 78 near
the external clouds is a dwarf companion or a part of a tidal structure.
However, the spectrum of this galaxy, SDSS J074240.37+651021.4, obtained at the
6-m telescope corresponds to the distant background galaxy.
