CIV Black Hole Mass Measurements with the Australian Dark Energy Survey
  (OzDES)
  Black hole mass measurements outside the local universe are critically
important to derive the growth of supermassive black holes over cosmic time,
and to study the interplay between black hole growth and galaxy evolution. In
this paper we present two measurements of supermassive black hole masses from
reverberation mapping (RM) of the broad CIV emission line. These measurements
are based on multi-year photometry and spectroscopy from the Dark Energy Survey
Supernova Program (DES-SN) and the Australian Dark Energy Survey (OzDES), which
together constitute the OzDES RM Program. The observed reverberation lag
between the DES continuum photometry and the OzDES emission-line fluxes is
measured to be $358^{+126}_{-123}$ and $343^{+58}_{-84}$ days for two quasars
at redshifts of $1.905$ and $2.593$ respectively. The corresponding masses of
the two supermassive black holes are $4.4 \times 10^{9}$ and $3.3 \times
10^{9}$ M$_\odot$, which are among the highest-redshift and highest-mass black
holes measured to date with RM studies. We use these new measurements to better
determine the CIV radius$-$luminosity relationship for high-luminosity quasars,
which is fundamental to many quasar black hole mass estimates and demographic
studies.
