The international research team, including Associate Professor Yutaka Fujita of Osaka University and Professor Keiichi Umezu of Academia Sinica, has established that the galaxy, the largest celestial body in the universe, grows according to one law and maintains the internal structure of the growing period. It was revealed for the first time in the world that there was.It is expected to be a clue to elucidate the evolutionary history of galaxy clusters and the universe itself.In addition, the National Institute of Space Physics of Italy, the University of Michigan in the United States, Princeton University in the United States, Hiroshima University, and the Institute of Space Telescope Science in the United States participated.
Until now, galaxy clusters (1 million light-years in size, celestial bodies containing hundreds to thousands of galaxies) have been regarded as the largest celestial bodies in the universe, and their main component is dark matter, which is not directly visible to the eye. It was difficult to measure the size and weight accurately.
The light of the galaxy behind the galaxy receives the gravity of the galaxy as it passes, and its path bends (gravitational lens effect), and the shape of the galaxy in the background of the galaxy looks distorted when viewed from the earth. ..If the distortion of the shape of many galaxies can be measured accurately, the gravitational field of the cluster of galaxies that are the lenses can be known, and the size and weight of the galaxy cluster can be accurately measured.
Therefore, we carried out a detailed observation project of the gravitational lens effect of 20 galaxy clusters using the ultra-high resolution "Hubble Space Telescope" and the wide-field "Subaru Telescope".Precise size and weight data for these clusters of galaxies were obtained.
The research group statistically examined this latest data and the temperature data of hot gas in the cluster of galaxies obtained by the Chandra X-ray astronomy satellite, and found that all the data follow a simple rule.Furthermore, computer simulations and theoretical analyzes have determined that the formation of this law is due to the fact that galaxy clusters are always in the growth phase and are still growing by constantly drawing in a large amount of surrounding matter due to their huge gravity. ..
Paper information:[The Astrophysical Journal] Discovery of a New Fundamental Plane Dictating Galaxy Cluster Evolution from Gravitational Lensing