Solar abundance corrections derived through 3D magnetoconvection
  simulations
  We explore the effect of the magnetic field when using realistic
three-dimensional convection experiments to determine solar element abundances.
By carrying out magnetoconvection simulations with a radiation-hydro code (the
Copenhagen stagger code) and through a-posteriori spectral synthesis of three
Fe I lines, we obtain evidence that moderate amounts of mean magnetic flux
cause a noticeable change in the derived equivalent widths compared with those
for a non-magnetic case. The corresponding Fe abundance correction for a mean
flux density of 200 G reaches up to ~0.1 dex in magnitude. These results are
based on space- and time-averaged line profiles over a time span of 2.5 solar
hours in the statistically stationary regime of the convection. The main
factors causing the change in equivalent widths, namely the Zeeman broadening
and the modification of the temperature stratification, act in different
amounts and, for the iron lines considered here, in opposite directions; yet,
the resulting $|\Delta\log\epsilon_{\odot}(Fe)|$ coincides within a factor two
in all of them, even though the sign of the total abundance correction is
different for the visible and infrared lines. We conclude that magnetic effects
should be taken into account when discussing precise values of the solar and
stellar abundances and that an extended study is warranted.
