We study the redshift evolution of galaxy pair fractions and merger rates for different types of galaxies using kinematic pairs selected from the DEEP2 Redshift Survey , combined with other surveys at lower redshifts .
By parameterizing the evolution of the pair fraction as ( 1 + z ) ^ { m } , we find that the companion rate increases mildly with redshift with m = 0.41 \pm 0.20 for all galaxies with -21 < M _ { B } ^ { e } < -19 .
Blue galaxies show slightly faster evolution in the blue companion rate with m = 1.27 \pm 0.35 , while red galaxies have had fewer red companions in the past as evidenced by the negative slope m = -0.92 \pm 0.59 .
The different trends of pair fraction evolution are consistent with the predictions from the observed evolution of galaxy number densities and the two-point correlation function for both the blue cloud and red sequence .
For the chosen luminosity range , we find that at low redshift the pair fraction within the red sequence exceeds that of the blue cloud , indicating a higher merger probability among red galaxies compared to that among the blue galaxies .
With further assumptions on the merger timescale and the fraction of pairs that will merge , the galaxy major merger rates for 0.1 < z < 1.2 are estimated to be \sim~ { } 10 ^ { -3 } h ^ { 3 } Mpc ^ { -3 } Gyr ^ { -1 } with a factor of 2 uncertainty .
At z \sim 1.1 , 68 % of mergers are wet , 8 % of mergers are dry , and 24 % of mergers are mixed , compared to 31 % wet mergers , 25 % dry mergers , and 44 % mixed mergers at z \sim 0.1 .
Wet mergers dominate merging events at z = 0.2 - 1.2 , but the relative importance of dry and mixed mergers increases over time .
The growth of dry merger rates with decreasing redshift is mainly due to the increase in the co-moving number density of red galaxies over time .
About 22 % to 54 % of present-day L ^ { * } galaxies have experienced major mergers since z \sim 1.2 , depending on the definition of major mergers .
Moreover , 24 % of the red galaxies at the present epoch have had dry mergers with luminosity ratios between 1:4 and 4:1 since z \sim 1 .
Our results also suggest that all three types of mergers play an important role in the growth of the red sequence , assuming that a significant fraction of wet/mixed mergers will also end up as red galaxies .
However , the three types of mergers lead to red galaxies in different stellar mass regimes : the wet mergers and/or mixed mergers may be partially responsible for producing red galaxies with intermediate masses while a significant portion of massive red galaxies are assembled through dry mergers at later times .