We report the results from a search for z > 6.5 quasars using the Dark Energy Survey ( DES ) Year 3 dataset combined with the VISTA Hemisphere Survey ( VHS ) and WISE All-Sky Survey .
Our photometric selection method is shown to be highly efficient in identifying clean samples of high-redshift quasars leading to spectroscopic confirmation of three new quasars - VDESJ 0244 - 5008 ( z = 6.724 ) , VDESJ 0020 - 3653 ( z = 6.834 ) and VDESJ 0246 - 5219 ( z = 6.90 ) - which were selected as the highest priority candidates in the survey data without any need for additional follow-up observations .
The new quasars span the full range in luminosity covered by other z > 6.5 quasar samples ( J _ { AB } = 20.2 to 21.3 ; M _ { 1450 } = -25.6 to -26.6 ) .
We have obtained spectroscopic observations in the near infrared for VDESJ 0244 - 5008 and VDESJ 0020 - 3653 as well as our previously identified quasar , VDESJ 0224 - 4711 at z = 6.50 from Reed et al .
( 2017 ) .
We use the near infrared spectra to derive virial black-hole masses from the full-width-half-maximum of the MgII line .
These black-hole masses are \simeq 1 - 2 \times 10 ^ { 9 } M _ { \odot } .
Combining with the bolometric luminosities of these quasars of L _ { bol } \simeq 1 - 3 \times 10 ^ { 47 } implies that the Eddington ratios are high - \simeq 0.6-1.1 .
We consider the C IV emission line properties of the sample and demonstrate that our high-redshift quasars do not have unusual C IV line properties when compared to carefully matched low-redshift samples .
Our new DES+VHS z > 6.5 quasars now add to the growing census of luminous , rapidly accreting supermassive black-holes seen well into the epoch of reionisation .