Dr Treu and his colleagues compared the mass the rings suggested was present with what they could actually see.
Treu博士和他的同事还比对了由光环推测而知的星系质量和他们实际直接观测所得的结果。
2
Dr Treu and his colleagues first identified the most promising places to look for Einstein rings-parts of the sky where two or more clusters of galaxies can be seen one behind the other.
Nevertheless, the first such ring was observed in 1987. Now, a group of astronomers led by Tommaso Treu of the University of California, Santa Barbara, have seen two concentric rings.