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

¹ Beijing Astronomical Observatory, National Astronomical Observatories, CAS, 20 Datun Road, Chaoyang District, Beijing 100012, PR China
² Joint Institute for VLBI in Europe, PO Box 2, 7990 AA Dwingeloo, The Netherlands
³ Leiden Observatory, PO Box 9513, 2300 RA Leiden, The Netherlands
⁴ Space Research Organization of the Netherlands, Sorbonnelaan 2, 3584 CA Utrecht, The Netherlands
⁵ Shanghai Astronomical Observatory, Shanghai 200030, PR China
⁶ Institute for Astronomy, University of Hawaii, 2680 Woodlawn Rd., Honolulu, HI 96822, USA

Corresponding author: R. Nan, nrd@bao.ac.cn

Received: 2 May 2001
Accepted: 18 October 2001

Abstract

Three high redshift radio galaxies, 1345+245 (4C 24.28, ), 1809+407 (4C 40.36, ) and 2349+289 (4C 28.58, ) 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 3 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.