Warmers: the missing link between Starburst and Seyfert galaxies

Abstract

Recent observational and theoretical work has shown that, as a consequence of mass loss in the form of stellar winds in the last stages of their evolution, massive stars can reach effective temperatures of more than 100000K, being observed as extreme WC or WO Wolf-Rayet stars. This paper examines the effect of these hot stars (which the authors call Warmers) in the evolution of metal-rich giant H II regions. The authors show that as a function of age, the emission-line spectrum of the H II region evolves first into a type 2 Seyfert spectrum and then into a Liner-type spectrum. The authors suggest that many of the active nuclei classified as type 2 Seyferts and Liners are not associated with a non-thermal power source but rather with violent star formation activity at high metal abundance.