据英国《新科学家》周刊网站7月4日报道，在宇宙中支撑宇宙网的基本架构暗物质首次被清楚地探测到。

众所周知，宇宙中的物质组成了一张网，宇宙网的丝状物将众多星系和星云串联起来在空旷的宇宙中扩展。这种丝状物由正常物质和暗物质构成。暗物质是人的肉眼无法直接看到的，约占宇宙质量的85%。

德国慕尼黑大学天文台的约尔格·迪特里希及其研究团队已探测到一个超星系团的丝状物中的暗物质成分。这个超星系团名为“阿伯尔222/223”，距地球约27亿光年。

巨大的丝状物产生的引力使得从地球发射至遥远星系的光束发生弯曲。迪特里希的研究团队利用这种光束，计算出“阿伯尔222/223”超星系团丝状物的质量并绘制出它的形状。附近正常物质的炽热气体发出的X射线表明，正常物质是该超星系团丝状物的组成部分，但仅占其质量的10%。其余部分一定是暗物质。迪特里希说，这表明这些丝状物是“将宇宙中的星系团连接在一起的暗物质网络的一部分”。

 

 

THE Dark matter underpinnings of cosmic web found

skeleton of dark matter that undergirds the cosmic web of matter in the universe has been clearly detected for first time.

We know that matter in the cosmos forms a web, with galaxies and clusters linked by filaments across mostly empty space. Filaments are made of normal matter and dark matter - the unseen stuff that makes up about 85 per cent of the universe's mass. Recent observations have seen the normal matter in such filaments.

Now Jörg Dietrich at the University Observatory in Munich, Germany, and his team have detected the dark matter component in a filament in a supercluster about 2.7 billion light years from us, called Abell 222/223.

The massive filament's gravity focuses the light travelling towards Earth from more distant background galaxies. The team used this light to calculate the filament's mass and shape. X-rays from the hot gas of normal matter in the vicinity showed that this matter lined up with the filament but made up only about 10 per cent of its mass. The rest must be dark matter (Nature, DOI: 10.1038/nature11224). This shows that the filament is "part of a network of dark matter that connects galaxy clusters throughout the universe", says Dietrich.