학술논문

Dark Energy Survey Year 1 results: measurement of the baryon acoustic oscillation scale in the distribution of galaxies to redshift 1.
Document Type
Article
Source
Monthly Notices of the Royal Astronomical Society. Mar2019, Vol. 483 Issue 4, p4866-4883. 18p.
Subject
*GALAXIES
*STELLAR evolution
*ANALYSIS of covariance
*GALACTIC redshift
*DARK energy
Language
ISSN
0035-8711
Abstract
We present angular diameter distance measurements obtained by locating the baryon acoustic oscillations (BAO) scale in the distribution of galaxies selected from the first year of Dark Energy Survey data. We consider a sample of over 1.3 million galaxies distributed over a footprint of 1336 deg2 with 0.6 < |$z$| photo < 1 and a typical redshift uncertainty of 0.03(1 + |$z$|⁠). This sample was selected, as fully described in a companion paper, using a colour/magnitude selection that optimizes trade-offs between number density and redshift uncertainty. We investigate the BAO signal in the projected clustering using three conventions, the angular separation, the comoving transverse separation, and spherical harmonics. Further, we compare results obtained from template-based and machine-learning photometric redshift determinations. We use 1800 simulations that approximate our sample in order to produce covariance matrices and allow us to validate our distance scale measurement methodology. We measure the angular diameter distance, D A, at the effective redshift of our sample divided by the true physical scale of the BAO feature, r d. We obtain close to a 4 per cent distance measurement of D A(⁠|$z$| eff = 0.81)/ r d = 10.75 ± 0.43. These results are consistent with the flat Λ cold dark matter concordance cosmological model supported by numerous other recent experimental results. [ABSTRACT FROM AUTHOR]