The clustering of radio galaxies: biasing and evolution versus stellar
  mass
  We study the angular clustering of $\sim 6\times 10^5$ NVSS sources on scales
$\gtrsim 50 h^{-1}$ Mpc in the context of the $\Lambda$CDM scenario. The
analysis partially relies on the redshift distribution of 131 radio galaxies,
inferred from the Hercules and CENSORS survey, and an empirical fit to the
stellar to halo mass (SHM) relation. For redshifts $z\lesssim 0.7$, the
fraction of radio activity versus stellar mass evolves as $f_{_{\rm RL}}\sim
M_*^{\alpha_0+\alpha_1 z}$ where $\alpha_0=2.529{\pm0.184}$ and
$\alpha_1=1.854^{+0.708}_{-0.761}$. The estimate on $\alpha_0$ is largely
driven by the results of Best et al. (2005), while the constraint on $\alpha_1$
is new. We derive a biasing factor $b(z=0.5)=2.093^{+0.164}_{-0.109}$ between
radio galaxies and the underlying mass.The function $b(z)=0.33z^2+0.85 z +1.6$
fits well the redshift dependence. We also provide convenient parametric forms
for the redshift dependent radio luminosity function, which are consistent with
the redshift distribution and the NVSS source count versus flux.
