When you buy through links on our articles, Future and its syndication partners may earn a commission.A section of the new 3D map from HETDEX data, showing concentrations of excited hydrogen (Lyman-alpha light) in the space between galaxies, which are marked by stars. | Credit: Maja Lujan Niemeyer/Max Planck Institute for Astrophysics/HETDEX, Chris Byrohl/Stanford University/HETDEXAstronomers have unveiled one of the most ambitious maps yet of the early universe, revealing a vast “sea of light” between galaxies that had remained otherwise hidden in previous surveys.Using data from the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX), researchers created a 3D map of light emitted by excited hydrogen 9 to 11 billion years ago, when the universe was in the throes of “cosmic noon,” its peak era of star formation. This specific form of light, known as Lyman-alpha, is produced when hydrogen atoms are energized by radiation from young, hot stars, creating a distinctive ultraviolet glow that can be traced across vast cosmic distances.AdvertisementAdvertisementThe experiment operates on the Hobby-Eberly Telescope at McDonald Observatory in Texas and goes beyond simply plotting galaxies to mapping structures that are faint and difficult to observe from the early universe, according to a statement.”Lyman alpha radiation is an important characteristic of galaxies at this period in the universe’s history, an era of vigorous star formation,” Robin Ciardullo, co-author of the study, said in the statement. “Previous to this study, the locations of fainter galaxies and gas, which also emit Lyman alpha radiation, have remained largely unknown.”Other giant maps of the universe have focused on cataloging individual galaxies — cosmic cities of light bright enough to stand out against the dark. Those surveys have been crucial for tracing large-scale structure and studying dark energy. But they miss something important: the faint glow of hydrogen gas and small, dim galaxies that lie between the bright beacons.”There’s a whole sea of light in the seemingly empty patches in between,” Maja Lujan Niemey …
