  More precise measurements of galaxy clustering will be provided by the next
generation of galaxy surveys such as DESI, WALLABY and SKA. To utilize this
information to improve our understanding of the Universe, we need to accurately
model the distribution of galaxies in their host dark matter halos. In this
work we present a new galaxy number density profile of haloes, which makes
predictions for the positions of galaxies in the host halo, different to the
widely adopted Navarro-Frenk-White (NFW) profile, since galaxies tend to be
found more in the outskirts of halos (nearer the virial radius) than an NFW
profile. The parameterised galaxy number density profile model of haloes is fit
and tested using the DARKSAGE semi-analytic model of galaxy formation. We find
that our galaxy number density profile model of haloes can accurately reproduce
the halo occupation distribution and galaxy two-point correlation function of
the DARKSAGE simulation. We also derive the analytic expressions for the
circular velocity and gravitational potential energy for this profile model. We
use the SDSS DR10 galaxy group catalogue to validate this galaxy number density
profile model of haloes. Compared to the NFW profile, we find that our model
more accurately predicts the positions of galaxies in their host halo and the
galaxy two-point correlation function.
