Astronomers utilized data gathered by NASA´s Chandra X-ray Observatory and various other optical telescopes to create an innovative method to study dark energy. They used four as models and the fact that massive and less massive galaxies show similarities of emissions in the X-ray spectrum. Utilizing these properties allowed for the establishment of distance parameters across the universe.
The method analyses the similarities that exists in the emission levels of X-rays in the outer reaches of galaxy clusters, where larger galaxies show identical gas emissions seen in the less massive versions. The similarities between massive and less massive galaxies allow scientist to compare them and deduce their distances in the expanding universe.
General theory of relativity
Based on Albert Einstein’s general theory of relativity, the rate of expansion is influenced by the properties of dark energy -- a form of energy that permeates all empty space and is the principal driving factor of the acceleration and expansion of the universe -- in addition to the quantities of matter in the universe, of which dark matter is the leading constituent..
This type of energy proliferates in al space and is responsible for the expansion and acceleration of the universe. It´s been calculated that the quantity of dark energy is of approximately 68% of the totality of energy known in the universe. This total represent the cosmological constant, which is equal to the density of dark energy in vacuum space. Scientists analyzed the emission measure of 320 hot galaxy clusters in distances that included a range in light-years from 760 million years to 6.7 billion years, which covers the era when dark energy caused the then decelerating universe to accelerate.
Scientists think that dark energy is one of the most mysterious subjects in #Cosmology and that new methods and techniques are needed in order to decipher the nature of this kind of phenomena.