Chapman S C, Blain A W, Ivison R J, Smail Ian R
California Institute of Technology, Pasadena, California 91125, USA.
Nature. 2003 Apr 17;422(6933):695-8. doi: 10.1038/nature01540.
A significant fraction of the energy emitted in the early Universe came from very luminous galaxies that are largely hidden at optical wavelengths (because of interstellar dust grains); this energy now forms part of the cosmic background radiation at wavelengths near 1 mm (ref. 1). Some submillimetre (submm) galaxies have been resolved from the background radiation, but they have been difficult to study because of instrumental limitations. This has impeded the determination of their redshifts (z), which is a crucial element in understanding their nature and evolution. Here we report spectroscopic redshifts for ten submm galaxies that were identified using high-resolution radio observations. The median redshift for our sample is 2.4, with a quartile range of 1.9-2.8. This population therefore coexists with the peak activity of quasars, suggesting a close relationship between the growth of massive black holes and luminous dusty galaxies. The space density of submm galaxies at redshifts over 2 is about 1,000 times greater than that of similarly luminous galaxies in the present-day Universe, so they represent an important component of star formation at high redshifts.
早期宇宙中发射出的相当一部分能量来自于极亮的星系，这些星系在光学波长下大多是隐藏的（由于星际尘埃颗粒）；现在这些能量构成了波长接近1毫米的宇宙背景辐射的一部分（参考文献1）。一些亚毫米波星系已从背景辐射中分辨出来，但由于仪器限制，对它们的研究一直很困难。这阻碍了对它们红移（z）的测定，而红移是理解它们的性质和演化的关键因素。在此，我们报告了利用高分辨率射电观测识别出的十个亚毫米波星系的光谱红移。我们样本的中值红移为2.4，四分位间距为1.9 - 2.8。因此，这群星系与类星体的活动高峰期共存，这表明大质量黑洞的增长与亮尘星系之间存在密切关系。红移超过2的亚毫米波星系的空间密度比当今宇宙中类似亮度星系的空间密度大约大1000倍，所以它们是高红移处恒星形成的重要组成部分。
