On October 19, an international team led by Xu Cong, a researcher at the National Observatory of the Chinese Academy of Sciences, published research results online in the international academic journal Nature: using the "China Sky Eye" FAST to image and observe the dense galaxy group " Stephen Five-stack Galaxy " and the surrounding sky area. It was found that the 31 huge atom gas structure with a scale of about 2 million light years is 20 times larger than the Milky Way. This is the largest atomic gas structure detected in the universe so far.
"This discovery is due to the unprecedented extreme dark and weak celestial detection ability brought by the ultra-high sensitivity of ' China Sky Eye '." Xu Cong said that the "China Sky Eye" can detect dark and weak radiation emitted by extremely thin diffuse atomic gas far away from the center of the galaxy, opening a new window for studying the origin of celestial bodies in the universe.
The distribution of atomic gases in the sky around the "Stephen Five-layer Galaxy" detected by the "China Sky Eye". | National Observatory of Chinese Academy of Sciences
According to reports, the origin of all celestial bodies in the universe is inseparable from atomic gas. For example, the main evolutionary process of galaxies is the process of constantly absorbing atomic gas from the universe and then converting it into stars. Observing the gas in the universe is a very important research topic in the field of astrophysics .
"China Sky Eye" under the starry sky (taken during maintenance, long-term exposure of photos). | Xinhua News Agency Photo by Oudongqu
"Stephen Five-layer Galaxy" has been the most popular galaxy group in the astronomy field since its discovery in 1877. This latest discovery shows that in the peripheral space far from the center of the galaxy cluster, there are large-scale low-density atomic gas structures. The formation of these gas structures is likely to be related to the history of intergalactic interactions when the Stephen Five-layer Galaxy was formed in the early days, and has been around for about 1 billion years.
"This discovery presents a challenge to studying the evolution of galaxies and their gases in the universe, because existing theories are difficult to explain why, for such a long time, these thin atomic gases have not been ionized by ultraviolet background radiation in the universe." Xu Cong said that this observation also predicts that there may be more such large-scale low-density atomic gas structures in the universe.
Editor: Fu Xinxin
Comprehensive: Xinhua News Agency, Chinese Academy of Sciences National Observatory
