Time delay measurement of Mg II line in CTS C30.10 with SALT
  We report 6 yr monitoring of a distant bright quasar CTS C30.10 (z = 0.90052)
with the Southern African Large Telescope (SALT). We measured the rest-frame
time-lag of $562\pm 2$ days between the continuum variations and the response
of the Mg II emission line, using the Javelin approach. More conservative
approach, based on five different methods, imply the time delay of
$564^{+109}_{-71}$ days. This time delay, combined with other available
measurements of Mg II line delay, mostly for lower redshift sources, shows that
the Mg II line reverberation implies a radius-luminosity relation very similar
to the one based on a more frequently studied H$\beta$ line.
