  We present the results of IRS low-resolution spectroscopy of 51 Seyfert
galaxies, part of a large Spitzer observing program to determine the mid-to-far
infrared spectral energy distributions of a well-defined sample of 87 nearby,
12 micron-selected Seyferts. We find that the spectra clearly divide into
groups based on their continuum shapes and spectral features. The infrared
spectral types appear to be related to the Seyfert types. Some features are
clearly related to a starburst contribution to the IR spectrum, while the
observed power-law continuum shapes, attributed to the AGN, may be dust or
non-thermal emission. Principal component analysis results suggest that the
relative contribution of starburst emission is the dominant cause of variance
in the spectra. We find that the Sy 2's show on average stronger starburst
contributions than the Sy 1's.

Astrophysics