Neutrinos and Quasars

Recall that Graham D was wondering about a phase transition at a redshift of $z = 0.6$, which is the lightest neutrino CMB temperature appearance threshold. Looking at the low $z$ quasar number curve from the 2dF QSO redshift survey we note a potential feature around $z = 0.6$, followed by the drop off towards $z = 0$.