We measure the angular power spectrum C _ { \ell } of radio galaxies in the NRAO VLA Sky Survey ( NVSS ) using two independent methods : direct spherical harmonic analysis and maximum likelihood estimation .
The results are consistent and can be understood using models for the spatial matter power spectrum and for the redshift distribution of radio galaxies at mJy flux-density levels .
A good fit to the angular power spectrum can only be achieved if radio galaxies possess high bias with respect to mass fluctuations ; by marginalizing over the other parameters of the model we derive a 68 \% confidence interval 1.53 < b _ { 0 } \times \sigma _ { 8 } < 1.87 , where b _ { 0 } is the linear bias factor for radio galaxies and \sigma _ { 8 } describes the normalization of the matter power spectrum .
Our models indicate that the majority of the signal in the NVSS C _ { \ell } spectrum is generated at low redshifts z \la 0.1 .
Individual redshifts for the NVSS sources are thus required to alleviate projection effects and probe directly the matter power spectrum on large scales .