[PPC2002] 2 , the SIMBAD biblio

We investigate redshift evolution in the galaxy merger and accretion rates, using a well-defined sample of 4184 galaxies with 0.12≤z≤0.55 and R_C≤21.5. We identify 88 galaxies in close (5≤r_p≤20 h^–1 kpc) dynamical (Δv≤500 km.s^–1) pairs. These galaxies are used to compute global pair statistics, after accounting for selection effects resulting from the flux limit, k-corrections, luminosity evolution, and spectroscopic incompleteness. We find that the number of companions per galaxy (for -21≤M^k,e_B≤-18) is N_c=0.0321±0.0077 at z=0.3. The luminosity in companions, per galaxy, is L_c=0.0294±0.0084x10¹⁰ h² L_☉. We assume that N_c is proportional to the galaxy merger rate, while L_c is directly related to the mass accretion rate. After increasing the maximum pair separation to 50 h^–1 kpc and comparing with the low-redshift SSRS2 pair sample, we infer evolution in the galaxy merger and accretion rates of (1+z)^2.3±0.7 and (1+z)^2.3±0.9, respectively. These are the first such estimates to be made using only confirmed dynamical pairs. When combined with several additional assumptions, this implies that approximately 15% of present epoch galaxies with -21≤M_B≤-18 have undergone a major merger since z=1.