  We use the Sloan Digital Sky Survey (SDSS) spectroscopic sample to constrain
the projected radial distribution of satellites around isolated ~ L* galaxies.
We employ mock galaxy catalogs derived from high-resolution cosmological
simulations to investigate the effects of interloper contamination and show
that interlopers significantly bias the estimated slope of the projected radial
distribution of satellites. We also show that the distribution of interlopers
around galaxies is expected to be non-uniform in velocity space because
galaxies are clustered and reside in crowded environments. Successful methods
of interloper contamination correction should therefore take into account
environments of the host galaxies. Two such new methods are presented and the
most reliable of them is used to correct for interloper contamination in
analyses of the SDSS galaxy sample. The best fit power-law slope of the
interloper-corrected surface density distribution of satellites, Sigma(R) ~
R^alpha, in the volume-limited SDSS sample is alpha ~ -1.7 +/- 0.1, independent
of the galaxy and satellite luminosities. Comparison with Lambda-CDM
simulations shows that the radial distribution of the SDSS satellites is more
concentrated than that of subhalos around galaxy-sized halos, especially at R <
100 kpc/h. The predicted dark matter radial distribution is somewhat more
concentrated than the profile of the SDSS satellites, but the difference is not
statistically significant for our sample.
