Gas-rich major merger rate of galaxies as a function of redshift. Circles are from this MASSIV data set, triangles are from de Ravel et al. (2009) and inverted triangles are from López-Sanjuan et al. (2011), both in VVDS-Deep, right-pointing triangles are from Lin et al. (2008) in DEEP2 redshift survey, squares are from López-Sanjuan et al. (2009b) in GOODS-S from morphological criteria, pentagons are from Xu et al. (2012) in the COSMOS field, and the hexagon is from Xu et al. (2012) in 2MASS/SDSS. The solid line is the least-squares fit of a power-law function, R_MM = 0.0048 × (1 + z)^3.95, to the data. The grey area marks the 3σ confidence interval in the fit. (A colour version of this plot is available at the electronic edition.)