169396 20260225153354.0 doi 10.1093/mnras/staa1191 sideral 142900 ART-2020-142900 eng Asorey, Jacobo (orcid)0000-0002-6211-499X HIR4: cosmology from a simulated neutral hydrogen full sky using Horizon Run 4 2020 The distribution of cosmological neutral hydrogen will provide a new window into the large-scale structure of the Universe with the next generation of radio telescopes and surveys. The observation of this material, through 21 cm line emission, will be confused by foreground emission in the same frequencies. Even after these foregrounds are removed, the reconstructed map may not exactly match the original cosmological signal, which will introduce systematic errors and offset into the measured correlations. In this paper, we simulate future surveys of neutral hydrogen using the Horizon Run 4 (HR4) cosmological N-body simulation. We generate H i intensity maps from the HR4 halo catalogue, and combine with foreground radio emission maps from the Global Sky Model, to create accurate simulations over the entire sky. We simulate the H i sky for the frequency range 700–800 MHz, matching the sensitivity of the Tianlai pathfinder. We test the accuracy of the fastICA, PCA, and log-polynomial fitting foreground removal methods to recover the input cosmological angular power spectrum and measure the parameters. We show the effect of survey noise levels and beam sizes on the recovered the cosmological constraints. We find that while the reconstruction removes power from the cosmological 21 cm distribution on large scales, we can correct for this and recover the input parameters in the noise-free case. However, the effect of noise and beam size of the Tianlai pathfinder prevents accurate recovery of the cosmological parameters when using only intensity mapping information. info:eu-repo/semantics/closedAccess All rights reserved http://www.europeana.eu/rights/rr-f/ 5.287 2020 ASTRONOMY & ASTROPHYSICS 16 / 68 = 0.235 2020 Q1 T1 2.057 2020 Space and Planetary Science 2020 Q1 Astronomy and Astrophysics 2020 Q1 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Parkinson, David Shi, Feng Song, Yong-Seon Ahn, Kyungjin Kim, Juhan Yao, Jian Zhang, Le Zuo, Shifan 495, 2 (2020), 1788-1806 Mon. not. R. Astron. Soc. Monthly notices of the Royal Astronomical Society 0035-8711 5045631 http://zaguan.unizar.es/record/169396/files/texto_completo.pdf Versión publicada 2750954 http://zaguan.unizar.es/record/169396/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:169396 articulos driver 2026-02-25-14:58:31 ARTICLE