Galaxy Clustering in the Completed SDSS Redshift Survey: The Dependence
  on Color and Luminosity
  We measure the luminosity and color dependence of galaxy clustering in the
SDSS DR7 main galaxy sample, focusing on the projected correlation function
w_p(r_p) of volume-limited samples. We interpret our measurements using halo
occupation distribution (HOD) modeling assuming a Lambda-CDM cosmology. The
amplitude of w_p(r_p) grows slowly with luminosity for L < L_* and increases
sharply at higher luminosities, with bias factor b(>L)=1.06+0.23(L/L_*)^{1.12}.
At fixed luminosity, redder galaxies have a stronger and steeper w_p(r_p), a
trend that runs steadily from the bluest galaxies to the reddest galaxies. The
individual luminosity trends for the red and blue galaxy populations are
strikingly different. Blue galaxies show a slow but steady increase of w_p(r_p)
with luminosity, at all scales. The large-scale clustering of red galaxies
shows little luminosity dependence until a sharp increase at L > 4L_*, but the
lowest luminosity red galaxies (0.04-0.25 L_*) show very strong clustering on
scales r_p < 2 Mpc/h. Most of the observed trends can be naturally understood
within the LCDM+HOD framework. The growth of w_p(r_p) with luminosity reflects
an overall shift in the halo mass scale, in particular an increase in the
minimum host halo mass Mmin. The mass at which a halo has, on average, one
satellite galaxy brighter than L is M_1 ~ 17 Mmin(L) over most of the
luminosity range. The growth and steepening of w_p(r_p) for redder galaxies
reflects the increasing fraction of galaxies that are satellite systems in high
mass halos instead of central systems in low mass halos, a trend that is
especially marked at low luminosities. Our extensive measurements, provided in
tabular form, will allow detailed tests of theoretical models of galaxy
formation, a firm grounding of semi-empirical models of the galaxy population,
and new cosmological tests.
