The Dark Energy Survey Year 3 high redshift sample: Selection, characterization and analysis of galaxy clustering
C Sánchez, A Alarcon, G M Bernstein, J Sanchez, S Pandey, M Raveri, J Prat, N Weaverdyck, I Sevilla-Noarbe, C Chang, E Baxter, Y Omori, B Jain, O Alves, A Amon, K Bechtol, M R Becker, J Blazek, A Choi, A Campos, A Carnero Rosell, M Carrasco Kind, M Crocce, D Cross, J DeRose, H T Diehl, S Dodelson, A Drlica-Wagner, K Eckert, T F Eifler, J Elvin-Poole, S Everett, X Fang, P Fosalba, D Gruen, R A Gruendl, I Harrison, W G Hartley, H Huang, E M Huff, N Kuropatkin, N MacCrann, J McCullough, J Myles, E Krause, A Porredon, M Rodriguez-Monroy, E S Rykoff, L F Secco, E Sheldon, M A Troxel, B Yanny, B Yin, Y Zhang, J Zuntz, T M C Abbott, M Aguena, S Allam, F Andrade-Oliveira, E Bertin, S Bocquet, D Brooks, D L Burke, J Carretero, F J Castander, R Cawthon, C Conselice, M Costanzi, M E S Pereira, S Desai, P Doel, C Doux, I Ferrero, B Flaugher, J Frieman, J García-Bellido, G Gutierrez, K Herner, S R Hinton, D L Hollowood, K Honscheid, D J James, K Kuehn, J L Marshall, J Mena-Fernández, F Menanteau, R Miquel, R L C Ogando, A Palmese, F Paz-Chinchón, A Pieres, A A Plazas Malagón, E Sanchez, V Scarpine, M Schubnell, M Smith, E Suchyta, G Tarle, D Thomas, C To,- Space and Planetary Science
- Astronomy and Astrophysics
Abstract
The fiducial cosmological analyses of imaging surveys like DES typically probe the Universe at redshifts z < 1. We present the selection and characterization of high-redshift galaxy samples using DES Year 3 data, and the analysis of their galaxy clustering measurements. In particular, we use galaxies that are fainter than those used in the previous DES Year 3 analyses and a Bayesian redshift scheme to define three tomographic bins with mean redshifts around z ∼ 0.9, 1.2 and 1.5, which extend the redshift coverage of the fiducial DES Year 3 analysis. These samples contain a total of about 9 million galaxies, and their galaxy density is more than 2 times higher than those in the DES Year 3 fiducial case. We characterize the redshift uncertainties of the samples, including the usage of various spectroscopic and high-quality redshift samples, and we develop a machine-learning method to correct for correlations between galaxy density and survey observing conditions. The analysis of galaxy clustering measurements, with a total signal-to-noise S/N ∼ 70 after scale cuts, yields robust cosmological constraints on a combination of the fraction of matter in the Universe Ωm and the Hubble parameter h, $\Omega _m h = 0.195^{+0.023}_{-0.018}$, and 2-3% measurements of the amplitude of the galaxy clustering signals, probing galaxy bias and the amplitude of matter fluctuations, bσ8. A companion paper (in preparation) will present the cross-correlations of these high-z samples with CMB lensing from Planck and SPT, and the cosmological analysis of those measurements in combination with the galaxy clustering presented in this work.