A recently discovered massive and extremely dense protocluster—the progenitor of a galaxy cluster—could be building one of the most massive structures in the universe today. Researchers surveying a region of the sky with the South Pole Telescope discovered a population of rare, extremely bright objects. Based on observations of carbon monoxide and ionized carbon emissions, the brightest of these consists of a protocluster of at least 14 gas-rich galaxies that are rapidly forming stars. The galaxy cluster core may have been at an advanced stage of formation when the universe was only 1.4 billion years old.
Original paper published April 25, 2018