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有读书笔记An intensity map of hydrogen 21-cm emission at redshift z approximately 0.8

Dr.LinZhen 添加于 2010-7-25 17:05 | 1735 次阅读 | 0 个评论
  •  作 者

    Chang T-C, Pen U-L, Bandura K, Peterson JB
  •  摘 要

    Observations of 21-cm radio emission by neutral hydrogen at redshifts z approximately 0.5 to approximately 2.5 are expected to provide a sensitive probe of cosmic dark energy. This is particularly true around the onset of acceleration at z approximately 1, where traditional optical cosmology becomes very difficult because of the infrared opacity of the atmosphere. Hitherto, 21-cm emission has been detected only to z = 0.24. More distant galaxies generally are too faint for individual detections but it is possible to measure the aggregate emission from many unresolved galaxies in the 'cosmic web'. Here we report a three-dimensional 21-cm intensity field at z = 0.53 to 1.12. We then co-add neutral-hydrogen (H i) emission from the volumes surrounding about 10,000 galaxies (from the DEEP2 optical galaxy redshift survey). We detect the aggregate 21-cm glow at a significance of approximately 4sigma.
  •  详细资料

    • 文献种类:期刊
    • 期刊名称: Nature
    • 期刊缩写: Nature
    • 期卷页: 2010  466 7305 463-465
    • 地址: [1] IAA, Academia Sinica, PO Box 23-141, Taipei 10617, Taiwan [2] CITA, University of Toronto, 60 St George Street, Toronto, Ontario M5S 3H8, Canada
    • ISBN: 0028-0836
    • 备注:PMID:20651685
  • 相关链接 DOI URL 

  •  Dr.LinZhen 的文献笔记  订阅

    高红移处的氢21厘米整合辐射图

    为了研究宇宙暗物质(为解释宇宙膨胀速度不断增加而假设存在的力)过去的效应,天文学家需要对极端宇宙距离处的结构有更多了解。21厘米的中性氢射电辐射线被看作是适用于这一目的的一个潜在的有用工具。此前,21厘米辐射只在星系中红移值为z = 0.24的地方被检测到。超过这个点的话,星系就太暗,无法被单独检测,但却有可能测量来自“宇宙网”(cosmic web)中很多未解来源的整合辐射。利用位于美国西弗吉尼亚的名为“Green Bank Telescope”的望远镜,研究人员绘制出了在红移值为0.53到1.12处的氢21厘米辐射的一个三维强度图。将来自DEEP2“光学星系红移巡天”项目所发现的大约1万个星系周围的H I辐射数据添加到该项研究所获得的这个数据集中,可以提供一幅21厘米整合辐射图,其统计显著性为4σ。

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