IT House reported on 15/0 that for a long time, the whereabouts of some ordinary matter (non-dark matter) in the universe have been bothering astronomers. It is estimated that ordinary matter accounts for about 0% of the total mass of the universe, yet about half of it is always "missing" in observable stars, galaxies, and other cosmic structures. Now, there may be an answer to that mystery.

A large team of researchers from multiple countries found thatThe diffuse hydrogen clouds that surround most galaxies are much larger than previously thought, and are large enough to explain much of the missing matter in the universe。 Simon Ferraro, an astronomer at the University of California, Berkeley and co-author of the study, said: "The measurements are consistent with the hypothesis of finding all the missing gases. The paper for this study has been published on the preprint server arXiv and is being peer-reviewed for publication in Physical Review Letters.

在此次研究中，研究人员利用美国亚利桑那州基特峰国家天文台的暗能量光谱仪（DESI）以及智利阿塔卡马宇宙学望远镜的数据展开调查。借助 DESI 的观测数据，团队将大约 700 万星系的图像叠加，以测量星系边缘微弱的电离氢气晕。这些气晕通常过于微弱，难以用常规方法观测到。因此，研究团队转而测量了这些气体如何使宇宙微波背景辐射（宇宙大爆炸遗留下来的弥漫在整个宇宙中的辐射）变暗或变亮。

The research team also found that clouds of ionized hydrogen formed ghostly, near-invisible filamentous structures between galaxies, IT House noted.If this cosmic network connects most galaxies in the universe, it spans enough to explain previously undetected matter.

The discovery could also change our understanding of the behavior of black holes. Scientists initially thought that supermassive black holes at the centers of most galaxies only eject gas early in their lives. However, the presence of such a wide range of diffuse gas clouds suggests that these black holes may be more active than previously thought.

"There is an assumption that black holes will occasionally turn on and off during so-called 'duty cycles.'" The study's lead author, Boriana Haziska, an astronomer at the University of California, Berkeley, said.

As a next step, the researchers plan to incorporate these new measurements into existing cosmological models. "There is a lot of interest in using our measurements for in-depth analysis, which will include this gas," Haziska said. ”