  We apply our recently developed, selfconsistent renormalization group (RG)
method to STM spectra of a two-impurity Kondo system consisting of two cobalt
atoms connected by a one-dimensional Cu chain on a Cu surface. This RG method
was developed to describe local spin screening in multi-impurity Kondo systems
in presence of the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction. Using the
RKKY interaction of a one-dimensional chain, we explain the experimentally
observed suppression and oscillation of the Kondo temperature, $T_K(y)$, as a
function of the length of the chain and the corresponding RKKY interaction
parameter $y$, regardless of the RKKY coupling being ferromagnetic or
antiferromagnetic.
