2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/12274We present multi-frequency radio continuum VLBI observations of the gravitational lens system B0218+357 carried out using a global VLBI network and the VLBA. The source has been observed with resolutions from 0.2 milliarcsec to 5 milliarcsec and displays interesting structure. The spectral properties of various components show that the lensed object is a standard flat spectrum radio source which has many self-absorbed components. Based on the flux ratio of the lensed images as a function of frequency we propose a simple model for the background radio source.5 pages, LaTeX, 3 figures, uses paspconf.sty and psfig.sty. To appear in "Highly Redshifted Radio Lines", eds. C. Carilli, S.Radford, K. Menten, G. Langston, (PASP: San Francisco)Astrophysicstext