An Infrared Comparison of Type-1 and Type-2 Quasars
  We model the optical to far-infrared SEDs of a sample of six type-1 and six
type-2 quasars selected in the mid-infrared. The objects in our sample are
matched in mid-IR luminosity and selected based on their Spitzer IRAC colors.
We obtained new targeted Spitzer IRS and MIPS observations and used archival
photometry to examine the optical to far-IR SEDs. We investigate whether the
observed differences between samples are consistent with orientation-based
unification schemes. The type-1 objects show significant emission at 3 micron.
They do not show strong PAH emission and have less far-IR emission on average
when compared to the type-2 objects. The SEDs of the type-2 objects show a wide
assortment of silicate features, ranging from weak emission to deep silicate
absorption. Some also show strong PAH features. In comparison, silicate is only
seen in emission in the type-1 objects. This is consistent with some of the
type-2s being reddened by a foreground screen of cooler dust, perhaps in the
host galaxy itself. We investigate the AGN contribution to the far-IR emission
and find it to be significant. We also estimate the star formation rate for
each of the objects by integrating the modeled far-IR flux and compare this
with the SFR found from PAH emission. We find the type-2 quasars have a higher
average SFR than the type-1 quasars based on both methods, though this could be
due to differences in bolometric luminosities of the objects. While we find
pronounced differences between the two types of objects, none of them are
inconsistent with orientation-based unification schemes.
