2006/12/01 by Marc Sarzi, Joseph C. Shields, Joe Shields +3
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysical Phenomena and Observations #Galaxies: Formation, Evolution, Phenomena #Luminosity #Population #Star formation #Stellar evolution #Stellar population #Supermassive black hole #Young stellar object #astro-ph
paper · pdf · doi:10.1017/s1743921307008848
published in Proceedings of the International Astronomical Union 2(S241), 489-492 (Cambridge University Press) · 4 pages, 2 figures, Proceedings of the IAU Symp. 241 "Stellar Populations as Building Blocks of Galaxies", held in La Palma in December 2006, eds. R. F. Peletier & A. Vazdekis
openalex publication_date 2006/12/01 · arxiv created 2007/03/30 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Abstract We present a preliminary analysis of the stellar populations in the central parsecs of a sample of 22 Seyfert 2 galaxies, based on a careful separation of nebular emission and stellar light in high-spatial resolution HST -STIS spectra. 10% of the surveyed nuclei display stellar populations of intermediate age, ∼1-2 Gyr old, whereas the remaining targets appear to be evenly split between objects showing only very old stellar populations and nuclei requiring also an additional blue featureless component, which we characterise by means of very young, few-Myr-old stars. The small fraction of stellar population of intermediate age seems to argue against the presence of such a young component, however, since the short lifetime of O-stars would imply recurrent star-formation episodes and the build-up over the last 1-2 Gyr of a detectable intermediate-age population. Additionally, a correlation between the luminosity of such a blue component and the emission from highly-ionised species, together with the general absence of Wolf-Rayet features, further suggests that the featureless continuum arises from the central engine rather than from star-forming regions. We discuss our results in the framework of the unification paradigm and of models for star formation close to supermassive black holes.