Simulated metal and HI absorption lines at the conclusion of
  Reionization
  We present a theoretical study of intergalactic metal absorption lines
imprinted in the spectra of distant quasars during and after the Epoch of
Reionization (EoR). We use high resolution hydrodynamical simulations at high
redshift ($4 <z<8$), assuming a uniform UV background Haardt--Madau 12,
post-processing with CLOUDY photoionization models and Voigt profile fitting to
accurately calculate column densities of the ions CII, CIV, SiII, SiIV and OI
in the intergalactic medium (IGM). In addition, we generate mock observations
of neutral Hydrogen (HI) at $z<6$. Our simulations successfully reproduce the
evolution of the cosmological mass density ($\Omega$) of CII and CIV, with
$\Omega_{CII}$ exceeding $\Omega_{CIV}$ at $z >6$, consistent with the current
picture of the tail of the EoR. The simulated CII exhibits a bimodal
distribution with large absorptions in and around galaxies, and some traces in
the lower density IGM. We find some discrepancies between the observed and
simulated column density relationships among different ionic species at $z=6$,
probably due to uncertainties in the assumed UV background. Finally, our
simulations are in good agreement with observations of the HI column density
distribution function at $z = 4$ and the HI cosmological mass density
$\Omega_{HI}$ at $4 < z < 6$.
