Minor vs Major Mergers: The Stellar Mass Growth of Massive Galaxies from
  z=3 using Number Density Selection Techniques
  We present a study on the stellar mass growth of the progenitors of local
massive galaxies with a variety of number density selections with
$n\le1\times10^{-4}\,\rm{Mpc^{-3}}$ (corresponding to
$M_*=10^{11.24}\rm{M_{\odot}}$ at z=0.3) in the redshift range $0.3<z<3.0$. We
select the progenitors of massive galaxies using a constant number density
selection, and one which is adjusted to account for major mergers. We find that
the progenitors of massive galaxies grow by a factor of four in total stellar
mass over this redshift range. On average the stellar mass added via the
processes of star formation, major and minor mergers account for $24\pm8\%$,
$17\pm15\%$ and $34\pm14\%$, respectively, of the total galaxy stellar mass at
$z=0.3$. Therefore $51\pm20\%$ of the total stellar mass in massive galaxies at
$z=0.3$ is created externally to their z=3 progenitors. We explore the
implication of these results on the cold gas accretion rate and size evolution
of the progenitors of most massive galaxies over the same redshift range. We
find an average gas accretion rate of $\sim66\pm32\,\rm{M_{\odot}yr^{-1}}$ over
the redshift range of $1.5<z<3.0$. We find that the size evolution of a galaxy
sample selected this way is on average lower than the findings of other
investigations.
