An international team of astronomers, led by Nicolas Laporte, from University College London (UK), has used the Atacama Large Millimeter / submillimeter Array (ALMA) telescope to observe the object A2744_YD4: the smallest and most remote galaxy ever seen by SOUL. The funny thing is that this young galaxy contains an abundance of ancient stardust formed by the deaths of a previous generation of stars; that is, due to the death of the first supernovae in the universe, which means that we will be able to advance a little more in the knowledge about how the first stars and galaxies in the universe were formed.
This ancient stardust found in the galaxy A2744_YD4 comes from when the universe was only 4% of its current age, barely 600 million years old, just in the stage of formation of the first stars and the first galaxies.
“The detection of so much stardust indicates that this galaxy was populated by the first supernovae,” explains Laporte.
The telescope, located in Chile and controlled by the European Southern Observatory (ESO), has been used together with other ESO instruments such as the X-Shooter of the Very Large Telescope (VLT), a set of telescopes located in Cerro Paranal (Chile ) and that make up the most advanced astronomical observatory in the world.
The observations of A2744_YD4 have been so clear since the galaxy lies behind a massive cluster of other known galaxies, the cluster Abell 2744, which acts as a ‘giant cosmic telescope’ (gravitational lens) that magnifies the observation by 1.8 times. . Thus, the experts detected very old stardust composed mainly of silicon, carbon and aluminum, key elements in the formation of planets or stars. In addition, a bright ionized oxygen emission has been detected in A2744_YD4, the farthest and therefore the earliest detection in the universe.
With this information we could determine one of the mysteries of astronomy: when exactly this ‘cosmic dawn’ occurred in which the first hot stars began to give light to the universe because “the estimated time is only 200 million years, so we are observing this galaxy shortly after its formation, “says Laporte.
