An X-ray survey of the 2Jy sample. I: is there an accretion mode
  dichotomy in radio-loud AGN?
  We carry out a systematic study of the X-ray emission from the active nuclei
of the 0.02<z<0.7 2Jy sample, using Chandra and XMM-Newton observations. We
combine our results with those from mid-IR, optical emission line and radio
observations, and add them to those of the 3CRR sources. We show that the
low-excitation objects in our samples \redit{show signs} of radiatively
inefficient accretion. We study the effect of the jet-related emission on the
various luminosities, confirming that it is the main source of soft X-ray
emission for our sources. We also find strong correlations between the
accretion-related luminosities, and identify several sources whose optical
classification is incompatible with their accretion properties. We derive the
bolometric and jet kinetic luminosities for the samples and find a difference
in the total Eddington rate between the low and high-excitation populations,
with the former peaking at ~1 per cent and the latter at ~20 per cent
Eddington. Our results are consistent with a simple Eddington switch when the
effects of environment on radio luminosity and black hole mass calculations are
considered. The apparent independence of jet kinetic power and radiative
luminosity in the high-excitation population in our plots supports a model in
which jet production and radiatively efficient accretion are not strongly
correlated in high-excitation objects, though they have a common underlying
mechanism.
