Hubble Space Telescope Imaging of Distant Galaxies: 4C 41.17 at Z = 3.8

Abstract

The Hubble Space telescope has been used to image the continuum emission from 4C 41.17 at z = 3.8, the most distant galaxy known. The galaxy was detected with good signal-to-noise ratio and was spatially resolved at the 0.1" (440 pc) HST resolution. The measured integrated flux density is in good agreement with the ground-based value (R~22). About 35% of this emission is in the form of a high brightness clumpy region extending by about 0.5" (1.7 kpc), whose morphology is remarkably similar to that of the radio components. A fainter more diffuse region of optical emission extends westward from the center of the nuclear complex for about 1.2" (5.3 kpc) out along the radio axis. The clumpiness of the optical emission and its close correspondence with the radio structure on the sub-kiloparsec scale is discussed in the light of current models for high-redshift galaxies. Our observations imply that the material in the center of this galaxy is clumpy on the subkiloparsec scale. If the emission is stellar, the luminosities are consistent with a mass of about 10^10^M_sun_ of stars in each <= 500 pc clump.