Clustering and Light Profiles of Galaxies in the Environment of 20 Ultra-Steep-Spectrum Radio Sources

We have analyzed galaxy properties in the neighborhood of 20 Ultra-SteepSpectrum Radio sources (USS) taken from the WISH catalog of De Breuck et al.(2002). Galaxies in these USS fields were identified in deep observations thatwere carried out in the K'-band using the OSIRIS imager at the CTIO 4mtelescope. We find a statistically significant signal of clustering around oursample of USS. The angular extension of the detected USS-galaxy clustering istheta_c~20" corresponding to a spatial scale ~120 h^{-1}kpc, assuming thesources are at z~1 in a Omega_m=0.3, Omega_{\Lambda}=0.7 model universe. Theseresults are in agreement with those obtained by Best (2000) for radiogalaxy-galaxy correlation, and Best et al. (2003) for radio-loud AGN-galaxycorrelation. We have also analyzed the light distribution of the galaxies byfitting Sersic's law profiles. Our results show no significant dependence ofthe galaxy shape parameters on the projected distance to the USS.Comment: Accepted for its publication in Astronomical Journal, 9 figure