For the first time, astronomers have created a three-dimensional map of the universe from 10 billion years ago that reveals not just the brightest galaxies, but the vast, faintly glowing web of smaller galaxies and gas clouds that connects them. Until now, traditional telescopes could only spot the cosmic equivalent of major cities, the biggest, brightest galaxies blazing with billions of stars, while the surrounding regions remained effectively invisible. Researchers working with the Hobby-Eberly Telescope Dark Energy Experiment in Texas used a clever new approach called Line Intensity Mapping, which instead of hunting for individual galaxies one by one, measures the total glow of hydrogen across enormous stretches of space. The result is like switching from a city map that only marks capitals to one that shows every town, village, and country road in between.
To build the map, supercomputers processed more than 600 million data readings from a patch of sky covering the equivalent of more than 2,000 full Moons, capturing light from a period when the universe was at the peak of its star-forming activity. The team then used the positions of already-known bright galaxies as anchors to calculate where fainter objects and gas clouds were glowing nearby, pulling structures into focus that had never been visible before. Scientists say only about five percent of all the data the telescope collects had ever been used for this kind of research, meaning the remaining 95 percent was sitting untouched and full of potential. The map now gives astronomers their first real look at how galaxies were actually distributed during one of the most important periods in cosmic history, and researchers say it opens the door to testing computer simulations of the universe against something real for the very first time.
Source: https://scitechdaily.com/astronomers-detect-a-vast-hidden-web-of-galaxies-in-the-early-universe/
