The metallicity in portions of high-redshift galaxies has been successfully measured thanks to the gas observed in absorption in the spectra of quasars , in the Damped Lyman- \alpha systems ( DLAs ) .
Surprisingly , the global mean metallicity derived from DLAs is about 1/10 ^ { th } solar at 0 \la z \la 4 leading to the so-called “ missing-metals problem ” .
In this paper , we present high-resolution observations of a sub-DLA system at z _ { abs } = 0.716 with super-solar metallicity toward SDSS J1323 - 0021 .
This is the highest metallicity intervening quasar absorber currently known , and is only the second super-solar absorber known to date .
We provide a detailed study of this unique object from VLT/UVES spectroscopy .
We derive [ Zn/H ] = + 0.61 , [ Fe/H ] = - 0.51 , [ Cr/H ] = < - 0.53 , [ Mn/H ] = - 0.37 , and [ Ti/H ] = - 0.61 .
Observations and photoionisation models using the CLOUDY software confirm that the gas in this sub-DLA is predominantly neutral and that the abundance pattern is probably significantly different from a Solar pattern .
Fe/Zn and Ti/Zn vary among the main velocity components by factors of \sim 3 and \sim 35 , respectively , indicating non-uniform dust depletion .
Mn/Fe is super-solar in almost all components , and varies by a factor of \sim 3 among the dominant components .
It would be interesting to observe more sub-DLA systems and determine whether they might contribute significantly toward the cosmic budget of metals .