Satellites around massive galaxies since z~2
  Accretion of minor satellites has been postulated as the most likely
mechanism to explain the significant size evolution of the massive galaxies
over cosmic time. Using a sample of 629 massive (Mstar~10^11 Msun) galaxies
from the near-infrared Palomar/DEEP-2 survey, we explore which fraction of
these objects has satellites with 0.01 Msat < Mcentral < 1 (1:100) up to z=1
and which fraction has satellites with 0.1 Msat < Mcentral < 1 (1:10) up to z=2
within a projected radial distance of 100 kpc. We find that the fraction of
massive galaxies with satellites, after the background correction, remains
basically constant and close to ~30% for satellites with a mass ratio down to
1:100 up to z=1, and ~15% for satellites with a 1:10 mass ratio up to z=2. The
family of spheroid-like massive galaxies presents a 2-3 times larger fraction
of objects with satellites than the group of disk-like massive galaxies. A
crude estimation of the number of 1:3 mergers a massive spheroid-like galaxy
experiences since z~2 is around 2. For a disk-like galaxy this number decreases
to ~1.
