Was the cosmic web of protogalactic material permeated by lobes of radio galaxies during the quasar era?

Evidence for extended active lifetimes (>10(8) yr) for radio galaxies impli es that many large radio lobes were produced during the "quasar era,", 1.5 < z < 3, when the comoving density of radio sources was 2-3 dex higher than the present level. However, both adiabatic and inverse Compton losses agai nst the intense microwave background substantially reduce the ages and numb ers of sources that are detected in flux-limited surveys. The realization t hat the galaxy-forming material in those epochs was concentrated in filamen ts occupying a small fraction of the total volume then leads to the conclus ion that radio lobes permeated much of the volume occupied by the protogala ctic material during that era. The sustained overpressure in these extended lobes may have played an important role in triggering the high inferred ra te of star formation at z > 1.5 and in the magnetization of the cosmic netw ork of filaments.