Scholarlink

<p>Galaxy clusters are the most massive, gravitationally bound structures in the Universe. They emerged through hierarchical structure formation of large-scale dark matter and baryon overdensities. Early galaxy ‘proto-clusters’ are believed to have substantially contributed to the cosmic star-formation rate density and served as ‘hotspots’ for the reionization of the intergalactic medium. Our understanding of the formation of these structures at the earliest cosmic epochs is, however, limited to sparse observations of their galaxy members or is based on phenomenological models and cosmological simulations. Here we report the detection of a large and coherent structure of neutral atomic hydrogen gas (H <span>i</span>) extending from a galaxy proto-cluster at redshift <i>z</i> = 5.4, one billion years after the Big Bang. The presence of this H <span>i</span> gas is revealed by strong damped Lyman-α absorption features observed in several background-galaxy spectra. Although the sight lines overall probe a large range in H <span>i</span> column densities, <i>N</i><sub>HI</sub> = 10<sup>20</sup> cm<sup>−2</sup> to 10<sup>23.5</sup> cm<sup>−2</sup>, they are similar across nearby sight lines, demonstrating that they probe the same dense neutral gas. This observation of a dense large-scale overdensity of cold neutral gas challenges current cosmological simulations and has strong implications for the reionization topology of the Universe.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

A dense web of neutral gas in a galaxy proto-cluster post-reionization

  • 期刊论文

  • 发表日期：

    2026年1月2日

查看全文
  • Kasper E. Heintz,
  • Jake S. Bennett,
  • Pascal A. Oesch,
  • Albert Sneppen,
  • Douglas Rennehan,
  • Clara L. Pollock,
  • Joris Witstok,
  • Renske Smit,
  • Simone Vejlgaard,
  • Chamilla Terp,
  • Umran S. Koca,
  • Gabriel B. Brammer,
  • Kristian Finlator,
  • Matthew J. Hayes,
  • Debora Sijacki,
  • Rohan P. Naidu,
  • Jorryt Matthee,
  • Francesco Valentino,
  • Nial R. Tanvir,
  • Páll Jakobsson,
  • Peter Laursen,
  • Darach J. Watson,
  • Romeel Davé,
  • Laura C. Keating,
  • Alba Covelo-Paz

摘要

Galaxy clusters are the most massive, gravitationally bound structures in the Universe. They emerged through hierarchical structure formation of large-scale dark matter and baryon overdensities. Early galaxy ‘proto-clusters’ are believed to have substantially contributed to the cosmic star-formation rate density and served as ‘hotspots’ for the reionization of the intergalactic medium. Our understanding of the formation of these structures at the earliest cosmic epochs is, however, limited to sparse observations of their galaxy members or is based on phenomenological models and cosmological simulations. Here we report the detection of a large and coherent structure of neutral atomic hydrogen gas (H i) extending from a galaxy proto-cluster at redshift z = 5.4, one billion years after the Big Bang. The presence of this H i gas is revealed by strong damped Lyman-α absorption features observed in several background-galaxy spectra. Although the sight lines overall probe a large range in H i column densities, NHI = 1020 cm−2 to 1023.5 cm−2, they are similar across nearby sight lines, demonstrating that they probe the same dense neutral gas. This observation of a dense large-scale overdensity of cold neutral gas challenges current cosmological simulations and has strong implications for the reionization topology of the Universe.