AGNs with composite spectra *
P. Véron 1,
A.C. Gonçalves 1, 2 and
M.-P. Véron-Cetty 1
Received 11 April 1996 / Accepted 22 July 1996
The use of the Baldwin et al. (1981) or Veilleux & Osterbrock (1987) diagnostic diagrams allows the unambiguous classification of the nuclear emission line regions of most galaxies into one of three categories: nuclear HII regions or starbursts, Seyfert 2 galaxies and Liners. However, a small fraction of them have a "transition" spectrum.
We present spectral observations of 15 "transition" objects at high-dispersion (66Å mm-1) around the H , and/or H , emission lines. We show that most of these spectra are composite, due to the simultaneous presence on the slit of a Seyfert nucleus and a HII region.
Seyfert 2s and Liners seem to occupy relatively small and distinct volumes in the three-dimensional space , , .
Key words: galaxies: nuclei galaxies: active galaxies: Seyfert
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© European Southern Observatory (ESO) 1997
Online publication: July 3, 1998