Astronomers Spot Ancient Stardust From the First Ever Stars in the Universe

  • Astronomers Spot Ancient Stardust From the First Ever Stars in the Universe

Astronomers Spot Ancient Stardust From the First Ever Stars in the Universe

The team estimate that A2744_YD4 formed approximately 200 million years after the Big Bang, making it one of the oldest galaxies ever observed. For the analysis, they used two telescopes in northern Chile, the Atacama Large Millimeter Array (ALMA) and the Very Large Telescope (VLT). Also, the light of this particular galaxy took 13.2 billion years to reach Earth, which is 96 percent of the total age of the universe.

In images rendered by ALMA, the galaxy A2744_YD4 appears as it existed when the universe was just 600 million years old, when the first stars and galaxies were still forming. This is due in part to a gravitational effect from a large cluster of galaxies between us and A2744_YD4 that bends the light from the distant galaxy and acts as a giant magnifying lens.

An worldwide team of astronomers is excited with the surprise from the paradox flowing from a young galaxy that is full of stardust from the early universe.

Scientists were surprised to find a high content of dust in the galaxy along with a rapid rate of star formation. The chemical elements are said to have been forged inside stars and are scattered across the cosmos as they die in spectacular supernova explosions.

This is the most distant, and hence earliest, detection of oxygen in the Universe, surpassing another ALMA result from 2016.

Their calculations showed mass of the dust in the galaxy was equivalent to six million times the mass of the sun. A2744_YD4 produces stars at a rate of 20 solar masses per year, which is a full 20 times the rate of our Milky Way's comparatively paltry star formation rate of 1 solar mass per year.

Lead researcher Nicolas Laporte, of University College London, said: "Not only is A2744_YD4 the most distant galaxy yet observed by ALMA, but the detection of so much dust indicates [that] early supernovae must have already polluted this galaxy".

One of the first places that happened was in galaxy A2744_YD4. She studied journalism at Douglass College, Rutgers University, and earned a Graduate Certificate of Science in astronomy from Swinburne University's Astronomy Online program. Based upon this rate, the group estimated that only about 200 million years were needed to form the dust seen in A2744_YD4.

In addition to identifying the dust from these early supernovae, ALMA also spotted emission from ionized oxygen in A2744_YD4 as well. In the very early universe, however, this dust was scarce, simply because the process of its creation and dispersion via supernovae hadn't had much time to complete.

This provides a great opportunity for ALMA to help study the era when the first stars and galaxies "switched on" - the earliest epoch yet probed. Our Sun, our planet and our existence are the products - 13 billion years later - of this first generation of stars. Says Laporte, "Further measurements of this kind offer the exciting prospect of tracing early star formation even further back into the early universe".