Assessing the dust selection bias in quasar absorbers at 0.7 < z< 1.6:
  Zn/Fe abundances in a radio-selected sample
  The Complete Optical and Radio Absorption Line System (CORALS) survey has
previously been used to demonstrate that the number density, gas and metals
content of z>1.6 damped Lyman alpha systems is not significantly
under-estimated in magnitude limited surveys. In this paper, a sample of strong
MgII absorbers selected from the optically complete 0.7 < z < 1.6 CORALS sample
of Ellison et al. is used to assess the potential of dust bias at intermediate
redshifts. From echelle spectra of all CORALS absorbers with MgII lambda 2796
and FeII lambda 2600 rest equivalent widths > 0.5 A in the redshift range 0.7 <
z < 1.6, we determine column densities of Zn, Cr, Fe, Mn and Si. The range of
dust-to-metals ratios and inferred number density of DLAs from the D-index are
consistent with optical samples. We also report the discovery of 4 new
absorbers in the echelle data in the redshift range 1.7 < z< 2.0, two of which
are confirmed DLAs and one is a sub-DLA, whilst the Lya line is not covered for
the fourth.
