Abstract
We present the first results of a survey for high redshift, z $\ge$ 6,
quasars using izY multi-colour photometric observations from the Dark Energy
Survey (DES). Here we report the discovery and spectroscopic confirmation of
the $z_AB, Y_AB$ = 20.2, 20.2 (M$_1450$ = $-$26.5) quasar DES
J0454$-$4448 with an emission line redshift of z = 6.10$\pm$0.03 and a HI near
zone size of 4.6 $\pm$ 1.7 Mpc.The quasar was selected as an i-band drop out
with i$-$z = 2.46 and z$_AB < 21.5$ from an area of $\sim$300 deg$^2$. It
is the brightest of our 43 candidates and was identified for follow-up
spectroscopically solely based on the DES i$-$z and z$-$Y colours. The quasar
is detected by WISE and has $W1_AB = 19.68$. The discovery of one
spectroscopically confirmed quasar with 5.7 $<$ z $<$ 6.5 and z$_AB łeq$
20.2 is consistent with recent determinations of the luminosity function at z
$\sim$ 6. DES when completed will have imaged $\sim$5000 deg$^2$ to
$Y_AB$ = 23.0 ($5\sigma$ point source) and we expect to discover $>$ 50-100
new quasars with z $>$ 6 including 3-10 with z $>$ 7 dramatically increasing
the numbers of quasars currently known that are suitable for detailed studies
including determination of the neutral HI fraction of the intergalactic medium
(IGM) during the epoch of Hydrogen reionization.
Users
Please
log in to take part in the discussion (add own reviews or comments).