Giant Radio Sources as a Probe of the Cosmological Evolution of the IGM. II. The Observational Constraint on the Model of Radio-Jets Propagation through the X-ray Halo-IGM Interface

Three limited samples of high-redshift radio sources of FRII-type are used to constrain the dynamical model for the jets' propagation through the two-media environment: the X-ray emitting halo with the power-law density profile surrounding the parent galaxy and the much hotter intergalactic medium (IGM) of a constant density. The model, originally developed by Gopal-Krishna and Wiita, is modified adopting modern values of its free parameters taken from recent X-ray measurements with the XMM-Newton and Chandra Observatories. We find that (i) giant-sized radio sources (≈1 Mpc) exist at redshifts up to z≈2, (ii) all newly identified the largest radio sources with 1