The Starburst-AGN connection: Weak-[N II] Seyferts and active Wolf-Rayet Galaxies

Anabela C. Gonçalves
European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching b. München,
Alemanha

T. Contini
Observatoire de Strasbourg, 11 rue de l’Université, F-67000 Strasbourg, França

D. Kunth
Institut d’Astrophysique de Paris, 98 bis Boulevard Arago, F-75014 Paris, França

P. Véron
Observatoire de Haute-Provence, F-04870 St. Michel l’Observatoire, França

M.-P. Véron-Cetty
Observatoire de Haute-Provence, F-04870 St. Michel l’Observatoire, França

Weak-[N II] Seyfert 2 galaxies represent a rather small subset of narrow emission-line galaxies with very low ( <=0.4) [N II]/Ha emission line ratios. The relative strength of other bright optical emission lines are, however, typical of Seyfert galaxies. Two ionization mechanisms can be advanced to account for their spectrophotometric properties: an explanation can be found in the presence of hot, massive stars like Wolf-Rayets; these could strongly contribute to (or even dominate) the energetics of the objects. An alternative to the "starburst scenario" relies on a particular geometry plus the presence of matter-bounded clouds. 
Wolf-Rayet galaxies (WRGs) are starburst systems with identified WR stars. Up to now, aprox. 130 WRGs have been compiled, most of which are "classical" star-forming galaxies. Only a few are known to have an active nucleus (AGN); however, WRGs har-boring an active nucleus should be powerful tools in the study of the AGN-Starburst connection.
Of all AGNs, weak-[N II] Seyfert 2s seem to constitute excellent WRGs candidates. Optical spectra aimed at studying a sample of such objects were obtained with EMMI at the NTT. Some (preliminary) results, presented in a poster, point to the discovery of a new active WRG.

Grupo de Astronomia da Universidade da Madeira - 2001