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Nuclear Starbursts in Nearby Seyfert Galaxies

A. Romano·A. Rifatto·S. Ciroi·P. Rafanelli·M. Dopita
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Abstract

Active galaxies are often associated with starbursts, which are possible sources of fuelling for the nuclear black holes. By means of optical (3500-7500 A) spectroscopic and narrow-band photometric data (H_alpha+[NII]6548,6583 and [OIII]5007) it is possible to detect starburst features in active nuclei and to study the correlation with Seyfert type and the surrounding environment. Here we present evidences of young stellar populations (HI high order Balmer lines) and extended H_alpha emission (indicative of HII regions) in 6 nearby Seyfert galaxies (z < 0.02). These very preliminary results seem to suggest that the nuclear starburst presence does not depend on the Seyfert type, favouring the hypothesis of the AGN Unified Model. By estimating the present SFR (< 10^6 years) and recent SFR (< 10^9 years) we observe that these objects have experienced most of star formation episodes in past epochs. This supports the hypothesis of a starburst-AGN connection, favouring an evolutionary scenario in which the AGN survives to the starburst.

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A. Romano, A. Rifatto, S. Ciroi, P. Rafanelli, M. Dopita. 2004-10-18. Nuclear Starbursts in Nearby Seyfert Galaxies. https://arxiv.org/abs/astro-ph/0410414

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