An international team of researchers has unveiled the most detailed 3D map of the distribution of matter in the Universe, and also improved the accuracy of dark energy constraints with the Hyper Suprime-Cam on the Subaru Telescope.
The Hyper Suprime-Cam (HSC) map, based on data from the Japanese Subaru telescope in Hawaii, has allowed astronomers to measure the gravitational distortion of images of approximately 10 million galaxies. The research results are published in the arXiv.org preprint database.
The Subaru Telescope has allowed scientists to view galaxies in even more detail and "deeper" than it was possible in the course of similar studies. For example, the Dark Energy Survey analyzes a much larger area of the sky with the same precision as the HSC, but only studies the Universe closest to us. HSC is studying a narrower area, but "looking" further, which allowed researchers to see fainter galaxies and create the most accurate map of the distribution of dark matter.
The scientists compared their map with fluctuations predicted by observations of the CMB from the Planck spacecraft. The results obtained by the HSC were slightly lower, but generally in line with the results of "Planck". The fact that both HSC and other weak lensing studies are getting lower results than Planck raises questions about whether dark energy actually behaves like Einstein's cosmological constant.
Comparison of substance distribution maps according to HSC data (left) and "Planck" (right) / © UTokyo
“Our map gives us the most detailed picture of how much dark energy is in the universe. She talks more about its properties and how it accelerates the expansion of the universe, - says Rachel Mandelbaum of Carnegie Mellon University. - HSC complements other studies. Combining these different projects will be a powerful tool in studying the nature of dark matter and dark energy."
Scientists received data and results during the first year of observations at HSC. Overall, the HSC study will gather information from five years of research. Astronomers will also study the evolution of galaxies and massive galaxy clusters over cosmic time, measuring objects such as supernovae and even the Milky Way.