Quantifying the anisotropy in the infrared emission of powerful AGN
  We use restframe near- and mid-IR data of an isotropically selected sample of
quasars and radio galaxies at 1.0 \leq z \leq 1.4, which have been published
previously, to study the wavelength-dependent anisotropy of the IR emission.
For that we build average SEDs of the quasar subsample (= type 1 AGN) and radio
galaxies (= type 2 AGN) from ~1-17 {\mu}m and plot the ratio of both average
samples. From 2 to 8 {\mu}m restframe wavelength the ratio gradually decreases
from 20 to 2 with values around 3 in the 10{\mu}m silicate feature. Longward of
12{\mu}m the ratio decreases further and shows some high degree of isotropy at
15 {\mu}m (ratio ~1.4). The results are consistent with upper limits derived
from the X-ray/mid-IR correlation of local Seyfert galaxies. We find that the
anisotropy in our high-luminosity radio-loud sample is smaller than in
radio-quiet lower-luminosity AGN which may be interpreted in the framework of a
receding torus model with luminosity-dependent obscuration properties. It is
also shown that the relatively small degree of anisotropy is consistent with
clumpy torus models.
