dark matter and dark energy tagged posts

A massive, young galaxy cluster seen in X-rays (blue), visible light (green), and infrared light (red). Image by X-ray: NASA/CXC/Univ of Missouri/M.Brodwin et al.; optical: NASA/STScI; infrared: JPL/CalTech

It’s a cosmic irony: the biggest things in the universe can also be the hardest to find. Elizabeth Blanton, a Boston University associate professor of astronomy, started hunting for distant galaxy clusters more than 20 years ago. A single galaxy cluster can be as massive as a quadrillion suns, yet faraway clusters are so faint that they are practically invisible to all but the biggest Earth-bound telescopes. Distant clusters hold pieces of the story of how the web-like structure of the universe first emerged and could help illuminate the true nature of dark energy and dark matter.

Now, ...

X-ray image of the XXL-South Field. Credit: ESA/XMM-Newton/XXL survey consortium/(S. Snowden, L. Faccioli, F. Pacaud)

ESO telescopes have provided an international team with the gift of the third dimension in a plus-sized hunt for the largest gravitationally bound structures in the Universe — galaxy clusters. Observations by the VLT and the NTT complement those from other observatories across the globe and in space as part of the XXL survey — one of the largest ever such quests for clusters.

Galaxy clusters are massive congregations of galaxies that host huge reservoirs of hot gas – the temperatures are so high that X-rays are produced...