Astronomers studied 320 galaxy clusters, the largest structures in the universe held together by gravity, to find information about the nature of dark energy. The clusters distance from Earth ranged from about 760 million light years to about 8.7 million light years. This is the era when the universe stopped decelerating and started to accelerate under the influence of dark energy.

The data scientists used were obtained from NASA’s Chandra X-ray Observatory, ESA’s Planck measurements on the Cosmic Microwave Background and observations of supernovae from a number of optical telescopes. Astronomers developed a new method to analyze the data and measure how quickly the universe was expanding at different times since the Big Bang. The rate of expansion is determined by the properties of dark energy and the amount of matter in the Universe. Scientists can then adjust the values of various cosmological parameters based on the rate of expansion. The latest results confirm previous studies that the properties of dark energy have not changed over billions of years. As Professor Morandi said, the nature of dark energy is one of the biggest mysteries in physics… and this new technique has the ability to provide a big leap forward in our understanding of dark energy.

 

Publication: Morandi et al. 2016

Source: Chandra Press Room