AAS 197, January 2001
Session 110. AGN Emission and Absorption Properties
Display, Thursday, January 11, 2001, 9:30-4:00pm, Exhibit Hall

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[110.11] The Origin of the Featureless Blue Continuum in Seyfert 2 Galaxies

H.R. Schmitt (NRAO-Socorro), R. Cid Fernandes (JHU, UFSC), T. Storchi-Bergmann (IF-UFRGS-Brazil), A.L. Kinney (NASA)

Evaluating the amount of blue featureless continuum and interpreting its origin has always been a problem in the analysis of the nuclear spectra of Seyfert 2 galaxies. Here we address this problem using IUE archival data and ground-based spectra, observed with matching apertures, of 30 Seyfert 2's. These spectra cover the spectral region from 1200Å\ to 10000Å. By comparing their optical stellar absorption features and continuum shapes with those of normal galaxies, and assuming that the best matching template to the optical part of the spectrum is also representative of the stellar population in the ultraviolet, we separate the contribution from stars to this band. We show that, in most of the cases, at least 50% of the observed emission at 1400Å\ is due to the host galaxy stellar population. We study the age composition of these spectra using a stellar population synthesis technique. We also show that previously observed differences between the ratio of ultraviolet to soft X-ray flux in Seyfert 1's and Seyfert 2's can be reconciled, within the Unified Model, once we take into account the stellar population contribution to the ultraviolet spectrum of Seyfert 2's. This work was supported by a NASA grant.

The author(s) of this abstract have provided an email address for comments about the abstract: schmitt@stsci.edu

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