Galaxy And Mass Assembly (GAMA): Galaxy close-pairs, mergers, and the
  future fate of stellar mass
  We use a highly complete subset of the GAMA-II redshift sample to fully
describe the stellar mass dependence of close-pairs and mergers between 10^8
Msun and 10^12 Msun. Using the analytic form of this fit we investigate the
total stellar mass accreting onto more massive galaxies across all mass ratios.
Depending on how conservatively we select our robust merging systems, the
fraction of mass merging onto more massive companions is 2.0%-5.6%. Using the
GAMA-II data we see no significant evidence for a change in the close-pair
fraction between redshift $z = 0.05-0.2$. However, we find a systematically
higher fraction of galaxies in similar mass close-pairs compared to published
results over a similar redshift baseline. Using a compendium of data and the
function $\gamma_M =A(1+z)m$ to predict the major close-pair fraction, we find
fitting parameters of $A = 0.021 \pm 0.001$ and $m = 1.53 \pm 0.08$, which
represents a higher low-redshift normalisation and shallower power-law slope
than recent literature values. We find that the relative importance of in-situ
star-formation versus galaxy merging is inversely correlated, with
star-formation dominating the addition of stellar material below Mstar and
merger accretion events dominating beyond Mstar. We find mergers have a
measurable impact on the whole extent of the GSMF, manifest as a deepening of
the dip in the GSMF over the next Gyr and an increase in Mstar by as much as
0.01-0.05 dex.
