Richard M. Plotkin, Scott F. Anderson, W. N. Brandt, Sera Markoff, Ohad Shemmer, Jianfeng Wu
We use data from the Wide-Field Infrared Survey Explorer (WISE) to perform a
statistical study on the mid-infrared (IR) properties of a large number
($\sim10^2$) of BL Lac objects --- low-luminosity Active Galactic Nuclei (AGN)
with a jet beamed toward the Earth. As expected, many BL Lac objects are so
highly beamed that their jet synchrotron emission dominates their IR spectral
energy distributions. In other BL Lac objects, however, the jet is not strong
enough to completely dilute the rest of the AGN emission. We do not see
observational signatures of the dusty torus from these weakly beamed BL Lac
objects. The lack of observable torus emission is consistent with suggestions
that BL Lac objects are fed by radiatively inefficient accretion disks.
Implications for the "nature vs. nurture" debate for FR I and FR II radio
galaxies are briefly discussed. Our study supports the notion that, beyond
orientation, accretion rate plays an important role in AGN unification.
View original:
http://arxiv.org/abs/1112.5162
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