• galaxies: high-redshift;
  • galaxies: ISM;
  • quasars: absorption lines;
  • quasars: individual: SDSS J 091826.16+163609.0;
  • quasars: individual: SDSS J033854.77−000521.0;
  • quasars: individual: PKS 0458−02


Recently, the number of detected galaxy counterparts of z≳ 2 damped Lyman α absorbers in quasi-stellar object (QSO) spectra has increased substantially so we today have a sample of 10 detections. Møller et al. in the year 2004 made the prediction, based on a hint of a luminosity–metallicity relation for DLAs, that H i size should increase with increasing metallicity. In this Letter we investigate the distribution of impact parameter and metallicity that would result from the correlation between galaxy size and metallicity. We compare our observations with simulated data sets given the relation of size and metallicity. The observed sample presented here supports the metallicity–size prediction: the present sample of DLA galaxies is consistent with the model distribution. Our data also show a strong relation between impact parameter and column density of H i. We furthermore compare the observations with several numerical simulations and demonstrate that the observations support a scenario where the relation between size and metallicity is driven by feedback mechanisms controlling the star formation efficiency and outflow of enriched gas.