We report the results of our radio , optical and infra-red studies of a peculiar radio source 4C 35.06 , an extended radio-loud AGN at the center of galaxy cluster Abell 407 ( z = 0.047 ) .
The central region of this cluster hosts a remarkably tight ensemble of nine galaxies , the spectra of which resemble those of passive red ellipticals , embedded within a diffuse stellar halo of \sim 1 arcmin size .
This system ( named the ‘ Zwicky ’ s Nonet ’ ) provides unique and compelling evidence for a multiple-nucleus cD galaxy precursor .
Multifrequency radio observations of 4C 35.06 with the Giant Meterwave Radio Telescope ( GMRT ) at 610 , 235 and 150 MHz reveal a system of 400 kpc scale helically twisted and kinked radio jets and outer diffuse lobes .
The outer extremities of jets contain extremely steep spectrum ( spectral index -1.7 to -2.5 ) relic/fossil radio plasma with a spectral age of a few \times ( 10 ^ { 7 } -10 ^ { 8 } ) yr .
Such ultra-steep spectrum relic radio lobes without definitive hot-spots are rare , and they provide an opportunity to understand the life-cycle of relativistic jets and physics of black hole mergers in dense environments .
We interpret our observations of this radio source in the context of the growth of its central black hole , triggering of its AGN activity and jet precession , all possibly caused by galaxy mergers in this dense galactic system .
A slow conical precession of the jet axis due to gravitational perturbation between interacting black holes is invoked to explain the unusual jet morphology .