Where Have All the Old Radio Sources Gone?
Extragalactic radio sources are generally assumed to be produced by
jets which transport energy and momentum from a nuclear source to the
extended raido lobes. This model is well defined for Type II sources,
and makes specific predictions for the evolution of the size and radio
power of these sources. In this paper I test these predictions
against the statistics of complete samples of Type II source. I find
the size distribution can plausibly be explained by a Gaussian
distribution of intrinsic jet power; but the luminosity distribution
cannot be explained by any simple model of the relativistic electron
population. In particular, many old sources should still be luminous,
predicting a large, steep-sectrum population which does not exist in
the sky. This is the ``old source problem''.
STATUS: in preparation