8 Mar 2017

An international team of astronauts has used the ALMA telescope to observe A2744_YD4, the youngest and most distant galaxy ever studied by the Chilean ESO instrument. Scientists were surprised to find that this group of “adolescent” stars contains a lot of interstellar dust, formed by the death of the previous generation of stars.

Stardust in the infant universe. The Chilean ESO ALMA observatory has focussed on a distant, young galaxy, full of...interstellar dust, seen by exploiting the gravitational lens effect. The galaxy is named A2744_YD4, and is the most distant group of stars ever seen by the ALMA telescope.
Jumping back in time, the ESO reporter has led us to the period when the universe was only 4% of its current age - around 600 million years. The galaxy in question, although “adolescent”, is wrapped in an unusually thick curtain of interstellar dust the equivalent of 6 billion times the mass of the Sun, formed by the remains of a previous generation of now-extinct stars. These grains of cosmic dust, mainly formed of silicon, carbon and aluminium, are “sown” throughout the universe after the death of a star by the violent explosion of a supernova.

Today, there is an abundance of them, and they are key to the birth of new stars; in the past, however, they were much more scarce. More in-depth studies on data from the ALMA observatory will provide further clues to solving the mystery of mysteries, about the period when the first supernovas were born and the power of the explosions flooded the infant universe with light.