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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 accret ing 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.
We use the GAMA I dataset combined with GALEX, SDSS and UKIDSS imaging to construct the low-redshift (z<0.1) galaxy luminosity functions in FUV, NUV, ugriz, and YJHK bands from within a single well constrained volume of 3.4 x 10^5 (Mpc/h)^{3}. The de rived luminosity distributions are normalised to the SDSS DR7 main survey to reduce the estimated cosmic variance to the 5 per cent level. The data are used to construct the cosmic spectral energy distribution (CSED) from 0.1 to 2.1 mum free from any wavelength dependent cosmic variance for both the elliptical and non-elliptical populations. The two populations exhibit dramatically different CSEDs as expected for a predominantly old and young population respectively. Using the Driver et al. (2008) prescription for the azimuthally averaged photon escape fraction, the non-ellipticals are corrected for the impact of dust attenuation and the combined CSED constructed. The final results show that the Universe is currently generating (1.8 +/- 0.3) x 10^{35} h W Mpc^{-3} of which (1.2 +/- 0.1) x 10^{35} h W Mpc^{-3} is directly released into the inter-galactic medium and (0.6 +/- 0.1) x 10^{35} h W Mpc^{-3} is reprocessed and reradiated by dust in the far-IR. Using the GAMA data and our dust model we predict the mid and far-IR emission which agrees remarkably well with available data. We therefore provide a robust description of the pre- and post dust attenuated energy output of the nearby Universe from 0.1micron to 0.6mm. The largest uncertainty in this measurement lies in the mid and far-IR bands stemming from the dust attenuation correction and its currently poorly constrained dependence on environment, stellar mass, and morphology.
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