.<\/p>\n
.
\n.<\/p>\n
By studying the growth and dynamics
\n of galaxy clusters, researchers from the RIKEN Advanced Science Institute, Wako,
\n and the Academia Sinica Institute of Astronomy and Astrophysics, Taiwan, have
\n provided valuable clues on the evolution of the universe.
\n.
\nHuge numbers of stars are not the only distinctive feature of galaxy clusters. Another
\n important component is the intracluster medium (ICM), a hot plasma consisting of electrons
\nand protons, that has a greater mass than the galaxies and extends throughout the
\nvast intergalactical space of the cluster
\n..
\nThe researchers focused their study on the ICM of the galaxy cluster known as A1689. They
\n analyzed x-ray observations made by the Japanese satellite Suzaku; its high sensitivity
\nfor x-ray radiation enabled the observation of A1689\u2019s ICM to very large distances away
\n from the center. The researchers also analyzed gravitational lensing effects, where\u2014following
\n Einstein\u2019s theory of relativity\u2014they estimated the total mass of the cluster by the way light from
\ndistant galaxies bent around different regions of A1689
\n..
\n\u201cFrom the gravitational lensing analysis, the mass distribution of A1689 is precisely known,\u201d notes
\n Madoka Kawaharada from the research team. \u201cTherefore, by adding x-ray information \u2026 to the
\n cluster outskirts, we [could] compare the gas dynamics directly with the mass distribution.
\nKawaharada and colleagues found significant interactions between the ICM and the large-scale
\nstructure of galaxies, sometimes called the \u2019cosmic web\u2019 that extends throughout the universe. At
\n the region where the A1689 cluster meets the large-scale structure, its ICM gets even hotter than <\/p>\n
its usual 20 megakelvin, with temperatures reaching 60 megakelvin. This suggests a heating effect by
\n the shock wave that develops where the hot ICM plasma meets \u2018colder\u2019 gas from the large-scale structure.
\nIn addition, the gravitational lensing data suggest that the ICM in the shock wave region is static, whereas
\n it is moving elsewhere, which supports it against the strong gravitational force of the cluster.
\nThese results provide a valuable insight into the dynamics of these huge cosmic structures, particularly if they
\n can be confirmed for other galaxy clusters, says Kawaharada. \u201cIf they behave similarly, it will be evidence
\n that galaxy clusters do interact with the large-scale structure, confirming that they are a continuously
\nevolving product of the structure formation in the universe.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"
. . . By studying the growth and dynamics of galaxy clusters, researchers from the RIKEN Advanced Science Institute, Wako, and the Academia Sinica Institute of Astronomy and Astrophysics, Taiwan, have provided valuable clues on the evolution of the universe. . Huge numbers of stars are not the only distinctive feature of galaxy clusters. Another … <\/p>\n