A 327 MHz VLBI study of high redshift radio galaxies 1345+245, 1809+407 and 2349+289

Abstract

Three high redshift radio galaxies, 1345+245 (4C 24.28, z = 2.889), 1809+407 (4C 40.36, z = 2.267) and 2349+289 (4C 28.58, z = 2.905) were observed with VLBI at 327 MHz giving an angular resolution of ≃40-100 mas and yielding images with the off-source noise level of 3σ ≃ 3.5 mJy/beam. On the centiarcsecond scale, the three sources are each characterized by two components with asymmetry both in flux density and in size. The compact components in the VLBI maps correspond to the hot spots in the VLA maps. No radio cores have been detected. The physical parameters for the components derived are consistent with a model in which shocks accelerate electrons in the hotspots.