Spitzer spectra of Seyfert galaxies

TL;DR

This paper presents high-resolution Spitzer IRS spectra of about 90 Seyfert galaxies, analyzing starburst and AGN contributions using mid-IR diagnostics and comparing results with models to understand galaxy evolution.

Contribution

It provides a comprehensive spectral analysis of a large Seyfert galaxy sample using mid-IR diagnostics and compares observations with models to quantify AGN and starburst contributions.

Findings

Starburst components quantified via PAH features and H2 emission.

AGN dominance measured through specific line ratios.

Results discussed in context of unification and evolution models.

Abstract

The Spitzer IRS high resolution spectra of about 90 Seyfert galaxies from the 12um Galaxy Sample are presented and discussed. These represent about 70% of the total complete sample of local Seyfert galaxies. The presence of starburst components in these galaxies can be quantified by powerful mid-IR diagnostics tools (i.e. 11.25um PAH feature equivalent width and the H_2 emission line intensity) as well as the AGN dominance can be measured by specific fine structure line ratios (e.g. [NeV]/[NeII], [NeV]/[SiII], etc.). The observed line ratios are compared to the results of semianalytical models, which can be used to compute the AGN and starburst contributions to the total luminosity of the galaxies. The results are also discussed in the light of unification and evolution models.