* Astronomy

Title: DES J0454-4448: Discovery of the First Luminous z \ge 6 Quasar from the Dark Energy Survey
Author: S. L. Reed, R. G. McMahon, M. Banerji, G. D. Becker, E. Gonzalez-Solares, P. Martini, F. Ostrovski, M. Rauch, T. Abbott, F. B. Abdalla, S. Allam, A. Benoit-Levy, E. Bertin, E. Buckley-Geer, D. Burke, A. Carnero Rosell, L. N. da Costa, C. DAndrea, D. L. DePoy, S. Desai, H. T. Diehl, P. Doel, C. E Cunha, J. Estrada, A. E. Evrard, A. Fausti Neto, D. A. Finley, P. Fosalba, J. Frieman, D. Gruen, K. Honscheid, D. James, S. Kent, K. Kuehn, N. Kuropatkin, O. Lahav, M. A. G. Maia, M. Makler, J. Marshall, K. Merritt, R. Miquel, J. Mohr, B. Nord, R. Ogando, A. Plazas, K. Romer, A. Roodman, E. Rykoff, M. Sako, E. Sanchez, B. Santiago, M. Schubnell, I. Sevilla, C. Smith, M. Soares-Santos, E. Suchyta, M. E. C. Swanson, G. Tarle, D. Thomas, D. Tucker, A. Walker, R. H. Wechsler

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 (M₁₄₅₀ = -26.5) quasar DES J0454-4448 with an emission line redshift of z = 6.10±0.03 and a HI near zone size of 4.6 ± 1.7 Mpc. The quasar was selected as an i-band drop out with i-z = 2.46 and zAB<21.5 from an area of ~300 deg². 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 W1AB=19.68. The discovery of one spectroscopically confirmed quasar with 5.7 < z < 6.5 and z_AB \leq 20.2 is consistent with recent determinations of the luminosity function at z ~ 6. DES when completed will have imaged ~5000 deg² to Y_AB = 23.0 (5sigma 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 reionisation.

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