Galaxy And Mass Assembly (GAMA): A forensic SED reconstruction of the
  cosmic star formation history and metallicity evolution by galaxy type
  We apply the spectral energy distribution (SED) fitting code ProSpect to
multiwavelength imaging for $\sim$7,000 galaxies from the GAMA survey at
$z<0.06$, in order to extract their star formation histories. We combine a
parametric description of the star formation history with a closed-box
evolution of metallicity where the present-day gas-phase metallicity of the
galaxy is a free parameter. We show with this approach that we are able to
recover the observationally determined cosmic star formation history (CSFH), an
indication that stars are being formed in the correct epoch of the Universe, on
average, for the manner in which we are conducting SED fitting. We also show
the contribution to the CSFH of galaxies of different present-day visual
morphologies, and stellar masses. Our analysis suggests that half of the mass
in present-day elliptical galaxies was in place 11 Gyr ago. In other
morphological types, the stellar mass formed later, up to 6 Gyr ago for
present-day irregular galaxies. Similarly, the most massive galaxies in our
sample were shown to have formed half their stellar mass by 11 Gyr ago, whereas
the least massive galaxies reached this stage as late as 4 Gyr ago (the
well-known effect of "galaxy downsizing"). Finally, our metallicity approach
allows us to follow the average evolution in gas-phase metallicity for
populations of galaxies, and extract the evolution of the cosmic metal mass
density in stars and in gas, producing results in broad agreement with
independent, higher-redshift observations of metal densities in the Universe.
