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Stellar population gradients in Seyfert 2 galaxies

Thaisa Storchi-Bergmann·Daniel I. Raimann·R. Gonzalez Delgado·H. R. Schmitt·R. Cid Fernandes·T. Heckman·Claus Leitherer
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Abstract

We study the variation of the stellar population properties as a function of distance from the nucleus for a sample of 35 Seyfert 2 galaxies using the technique of stellar population synthesis. We sample regions at the galaxies with dimensions in the range 200 x 200 to 400 x 400 pc and compare the synthesis results with those of a control sample of non-Seyfert galaxies. We find that both at the nucleus and up to 3 kpc from it the oldest age component (10 Gyr) presents a smaller contribution to the total flux in the Seyfert than in the non-Seyfert galaxies of the same Hubble type, while the components younger than 100 Myr present a larger contribution in the Seyfert's than in non-Seyferts. In addition, while for the non-Seyferts clear gradients are present, in which the contribution of the oldest components decrease with distance from the nucleus and the contribution of the 1 Gyr component increases -- we do not find such gradients in most Seyferts. These results suggest that the AGN-starburst connection is a large scale phenomenon affecting not only the inner few hundred parsecs, but the inner kiloparsecs.

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Thaisa Storchi-Bergmann, Daniel I. Raimann, R. Gonzalez Delgado, H. R. Schmitt, R. Cid Fernandes, T. Heckman, Claus Leitherer. 2002-11-21. Stellar population gradients in Seyfert 2 galaxies. https://arxiv.org/abs/astro-ph/0211474

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