A search for non-hidden broad-line region Seyfert 2 galaxies
  According to the unified model of active galactic nuclei, Seyfert 2 galaxies
are physically the same as Seyfert 1 objects and they possess a broad-line
region (BLR), but it is hidden from the observer due to their orientation. In
the past few years, various authors reported that not all Seyfert 2 galaxies
harbor a BLR. We compiled a sample of 38 Seyfert 2 galaxies to find non-hidden
broad-line region (non-HBLR) objects. Using the theory of Nicastro et al. which
suggests the existence of a critical value of the Eddington ratio below which
BLR can't be formed, we found 26 non-HBLR Seyfert 2 candidates. We found also
that 5 of these 26 non-HBLR objects could be low-ionization nuclear
emission-line regions (LINERs).
