Chemical enrichment in isolated barred spiral galaxies
  To investigate the role of bars in the chemical evolution of isolated disc
galaxies, we performed a series of 39 gas dynamical simulations of isolated
barred and unbarred galaxies with various masses, initial gas fractions, and
AGN feedback models. The presence of a bar drives a substantial amount of gas
toward the central region of the galaxy. In the most massive galaxies, this
results in a violent starburst, followed by a drop in star formation resulting
from gas exhaustion. The time delay between Type Ia and Type II supernovae
explosions means that barred galaxies experience a rapid increase in [O/H] in
the central region, and a much more gradual increase in [Fe/H]. In unbarred
galaxies, star formation proceeds at a slow and steady rate, and oxygen and
iron are produced at steady rates which are similar except for a time offset.
Comparing the abundance ratios in barred and unbarred galaxies with the same
central stellar mass $M_*$, we find in barred galaxies an enhancement of 0.07
dex in [O/H], 0.05 dex in [Fe/H], and 0.05 dex in [O/Fe]. The [O/H] enhancement
is in excellent agreement with observations from the SDSS. The initial gas
fraction has very little effect on the abundance ratios in barred and unbarred
galaxies, unless the galaxies experience a starburst. We considered AGN-host
galaxies located near the bottom of the AGN regime,
$M_*>3\times10^{10}M_\odot$, where AGN feedback dominates over supernovae
feedback. We found that the impact of AGN feedback on the central abundances is
marginal.
