They contain a lot of dark matter, as well as hot gases and colder "ordinary matter", such as stars and colder gases. In a new study published in Nature Communications, an international team led by astrophysicists from the University of Michigan and the University of Birmingham, England, used data from the Cluster Substructure Study (LoCuSS) of our Milky Way galaxy to measure the connections among the three main mass components that make up a cluster of galaxies-dark matter, hot gas and stars.
The research team members spent 12 years collecting data, and the wavelength span of these data was100000 times. Chandra and xmm-Newton satellites, ROSAT all-day observation satellite, Subaru telescope, British infrared telescope (UKIRT), Mayall telescope, Sunyaev Zeldovich array and Planck satellite were used.
Using the complex statistical model and algorithm established by Dr. Arya Farahi of the University of Michigan during his doctoral research, the research team concluded that the sum of gas and stars in the cluster studied is almost a fixed proportion of the mass of dark matter. This means that when a star forms, the amount of hot gas available will be reduced proportionally, said Dr. Falahi, a postdoctoral researcher in Michael Williams who is currently in the Physics Department of Carnegie Mellon University. This confirms the popular cold dark matter theory prediction.
Dr. Graham Smith from the School of Physics and Astronomy of Birmingham University and the principal researcher of LoCuSS said: A certain amount of matter in the universe collapses to form galaxy clusters. But once formed, these clusters are' closed boxes'. Hot gases either form stars or remain gaseous, but the total number remains the same. Professor August E. Evrard of the University of Michigan said: This research is driven by the investment in telescopes for more than ten years.
Using these high-quality data, astronomers can characterize 4 1 adjacent galaxy clusters and find a special relationship, especially the anti-correlation behavior between star mass and hot gas clusters. This is very important, because the combination of these two measurement methods provides us with the best indication of the quality of the whole system. These discoveries are crucial for astronomers to measure the overall nature of the universe. By better understanding the internal physics of galaxy clusters, researchers will be able to better understand the behavior of dark energy and the process behind the expansion of the universe.
The galaxy cluster itself is fascinating, but it is still a mysterious structure in many ways. Unlocking the complex astrophysics that controls the structure of these systems will open many doors to a wider understanding of the universe. In essence, if you want to understand how the universe works, you need to understand galaxy clusters. Due to the emergence of a new generation of telescopes, this kind of data studied by the team will increase by several orders of magnitude in the next few decades. The new generation of telescopes includes the large-scale meteorological observation telescope (LSST) currently under construction in Chile and a new X-ray satellite, e-ROSITA, both of which will start observation in the early 1920s. These measurements laid the foundation for the precise science of galaxy clusters!