Compton Dominance and the Blazar Sequence
  Does the "blazar sequence" exist, or is it a result of a selection effect,
due to the difficulty in measuring the redshifts of blazars with both high
synchrotron peak frequencies (\gtrsim 10^{15} Hz) and luminosities (\gtrsim
10^{46} erg s^{-1})? We explore this question with a sample of blazars from the
Second Catalog of Active Galactic Nuclei (AGN) from the Fermi Large Area
Telescope (LAT). The Compton dominance, the ratio of the peak of the Compton to
the synchrotron peak luminosities, is essentially a redshift-independent
quantity, and thus crucial to answering this question. We find that a
correlation exists between Compton dominance and the peak frequency of the
synchrotron component for all blazars in the sample, including ones with
unknown redshift. We then construct a simple model to explain the blazar
properties in our sample, where the difference between sources is due to only
the magnetic field of the blazar jet emitting region, the external radiation
field energy density, and the jet angle to the line of sight, with the magnetic
field strength and external energy density being correlated. This model can
reproduce the trends of the blazars in the sample, and predicts blazars may be
discovered in the future with high synchrotron peak frequencies and
luminosities. At the same time the simple model reproduces the lack of
high-synchrotron peaked blazars with high Compton dominances (\gtrsim 1).
