The Origin of Stellar Populations in Primeval Elliptical Galaxies at Redshift z～2

我们用斯巴鲁望远镜拍摄了一个非常遥远、异常明亮、巨大的椭圆星系的红外光谱。与以前的研究相比，这个星系似乎与它在本地宇宙中的表亲相似。它的大小似乎是正常的质量，其速度分散是符合其大尺寸。这项研究加深了关于一些椭圆星系如何以及为什么在宇宙演化的早期就达到了它们的完整尺寸，而其他非常紧凑的星系随着时间的推移体积增加了一百倍的谜团。

We have used the Subaru Telescope to take infrared spectra of a very distant, unusually bright, and massive elliptical galaxy. In contrast with previous studies, this galaxy appears to be similar to its cousins in the local Universe. Its size appears to be normal for its mass, and its velocity dispersion is consistent with its large size. This research deepens the puzzle as to how and why some elliptical galaxies seem to reach their full size very early in the evolution of the Universe while other, very compact ones increase in volume a hundredfold over time.