首页> 外文期刊>Nature >Galaxies at redshifts 5 to 6 with systematically low dust content and high [C II] emission
【24h】

Galaxies at redshifts 5 to 6 with systematically low dust content and high [C II] emission

机译:红移5到6的星系,系统地含尘量低,[C II]排放高

获取原文
获取原文并翻译 | 示例
           

摘要

The rest-frame ultraviolet properties of galaxies during the first three billion years of cosmic time (redshift z > 4) indicate a rapid evolution in the dust obscuration of such galaxies(1-3). This evolution implies a change in the average properties of the interstellar medium, but the measurements are systematically uncertain owing to untested assumptions(4,5) and the inability to detect heavily obscured regions of the galaxies. Previous attempts to measure the interstellar medium directly in normal galaxies at these red-shifts have failed for a number of reasons(6-9), with two notable exceptions(10,11). Here we report measurements of the forbidden C II emission (that is, [C II]) from gas, and the far-infrared emission from dust, in nine typical star-forming galaxies about one billion years after the Big Bang (z approximate to 5-6). We find that these galaxies have thermal emission that is less than 1/12 that of similar systems about two billion years later, and enhanced [C II] emission relative to the far-infrared continuum, confirming a strong evolution in the properties of the interstellar medium in the early Universe. The gas is distributed over scales of one to eight kiloparsecs, and shows diverse dynamics within the sample. These results are consistent with early galaxies having significantly less dust than typical galaxies seen at z < 3 and being comparable in dust content to local low-metallicity systems(12).
机译:在宇宙的前30亿年(红移z> 4)中,星系的静止帧紫外线特性表明此类星团的尘埃遮盖力迅速发展(1-3)。这种演变意味着星际介质平均特性的变化,但由于未经检验的假设(4,5)以及无法检测到星系的严重遮挡区域,因此测量结果在系统上是不确定的。先前尝试在这些红移状态下直接在正常星系中测量星际介质的尝试失败了,原因有很多(6-9),但有两个值得注意的例外(10,11)。在这里,我们报告了在大爆炸后大约十亿年(九周)近似于九个典型的恒星形成星系中,来自气体的禁止的C II发射(即[C II])和来自尘埃的远红外发射的测量值。 5-6)。我们发现这些星系的热辐射小于二十亿年后类似系统的热辐射的1/12,并且相对于远红外连续体,其[C II]辐射增强,这证实了星际特性的强演化在早期的宇宙中。气体的分布范围为1至8千帕秒,并在样品中显示出不同的动态。这些结果与早期星系的尘埃相一致,后者的尘埃比z <3时的典型星系少得多,并且尘埃含量与本地低金属性系统相当(12)。

著录项

  • 来源
    《Nature》 |2015年第7557期|455-458|共4页
  • 作者单位

    CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA|CALTECH, Pasadena, CA 91125 USA;

    Natl Radio Astron Observ, Socorro, NM 87801 USA|Univ Cambridge, Cavendish Lab, Astrophys Grp, Cambridge CB3 0HE, England;

    New Mexico Inst Min & Technol, Socorro, NM 87801 USA;

    Univ Texas Austin, Dept Astron, Austin, TX 78712 USA;

    Cornell Univ, Dept Astron, Ithaca, NY 14853 USA;

    Natl Radio Astron Observ, Charlottesville, VA 22903 USA;

    ETH, Inst Astron, CH-8093 Zurich, Switzerland;

    Aix Marseille Univ, CNRS, LAM, UMR 7326, F-13388 Marseille, France;

    Argelander Inst Astron, D-53121 Bonn, Germany;

    Aix Marseille Univ, CNRS, LAM, UMR 7326, F-13388 Marseille, France;

    Natl Radio Astron Observ, Charlottesville, VA 22903 USA;

    CALTECH, Pasadena, CA 91125 USA;

    Univ Zagreb, Dept Phys, Zagreb 10002, Croatia;

    CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA|CALTECH, Pasadena, CA 91125 USA;

  • 收录信息 美国《科学引文索引》(SCI);美国《工程索引》(EI);美国《生物学医学文摘》(MEDLINE);美国《化学文摘》(CA);
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号