Astronomers have used X-ray data from the NASA Chandra X-Ray Observatory along with data from the ESA XMM-Newton combined with UV data from the Sloan Digital Sky Survey to gather new evidence that could make astronomers re-evaluate their understanding of the universe. The data gathered lends proof that an invisible force called dark energy may be getting stronger over time. Before the new data, dark energy was thought to be constant over time.
Scientists say that dark energy, which was discovered 20-years ago, is a type of energy that permeates all space and causes the expansion of the universe. Dark energy is thought to make up about 70% of the composition of the universe. Most studies currently use something called the “concordance model” that uses dark energy as a “cosmological constant.”
That means the energy is constant through space and time. However, the new evidence used a new method to determine distances to quasars using data on about 1,600 quasars. The data gave astronomers distances to the quasars that are much further from Earth than the observed supernovas. The data allows researchers to extend calculations of the expansion rate of the Universe to greater distances and earlier times in the evolution of the Universe.
The team found the expansion rate to be different from predictions made by the concordance model. The data appears to support that the universe is now expanding faster than the trajectory it was on shortly after the big bang. The team is confident their data is correct.
If the new data is confirmed it would imply that dark energy isn’t the cosmological constant it was through to be. Confirmation could also help explain why there is an ongoing mismatch between the Hubble constant for the rate of Universe expansion and data based on measurements of the Cosmic Microwave Background. The team plans to use a larger sample of data from Chandra observations to attempt to test their theory further.