To the list of cosmic superlatives need to now be added a new item: the oldest dust.
It is not behind your refrigerator or underneath the bed. It’s in a galaxy with only a number for a name in a constellation referred to as Sculptor, and so far away that its distance barely has any meaning. The light from A2744_YD4, as it is known, has been on its way to us for 13.2 billion years, considering that the universe was only 600 million years old.
Where the galaxy is “now” is only a mathematical extrapolation — about 30 billion light-years from right here, according to the regular cosmological math. An international group led by Nicolas Laporte of University College London, using the Atacama Massive Millimeter/submillimeter Array, or ALMA, a radio telescope in Chile, was capable to see this galaxy only since its light had been amplified by the gravity of a enormous cluster of galaxies lying correct in front of it.
Interspersed with radio emissions from stars, the astronomers were surprised to uncover the characteristic heat emanations from some six million solar masses of dust. The dust consisted of tiny grains of carbon, silicon and aluminum — an austere and unevolved version of the identical stuff beneath your fingernails, and in the dust bunnies beneath your bed. The big news is that it existed in such quantities only 600 million years following the Big Bang.
The primordial universe, as it emerged from the Massive Bang, consisted nearly entirely of hydrogen and helium, the simplest and lightest elements, according to astronomers, with only a slight trace of lithium. The heavier elements, required for planets and us amongst other factors, had been manufactured in stars, which then blew up. As the story goes, the exploding stars scattered their ashes across space exactly where they could be incorporated into new stars and repeat the cycle, steadily enriching the chemistry of the cosmos.
The new observations show that this relentless progression from dust to better-and-greater dust had already been jump-started by the time the universe was just 600 million years old. The 1st stars had already been born and died in less than 200 million years in a wave of supernova explosions, according to Richard Ellis, of the European Southern Observatory and the University College London, and a single of the leaders of a paper published in Astrophysical Journal Letters.
At the time, in the child boom years of the universe, the young galaxy was feeling its oats, pumping out 20 new stars a year. By comparison the Milky Way, our personal galaxy, nowadays births only 1 star a year.
The new results augur a vibrant future for the ALMA telescope, a $ 1.5 billion array of antennas tuned to record the heat emanations of stars and dust, and NASA’s coming James Webb Space Telescope, designed to investigate the early days of the universe. “More observations must pinpoint the period when galaxies began to be first polluted by heavy components,” Dr. Ellis stated in an e mail from London.
“Until now, research of early galaxies have largely been primarily based on measures of colors and masses,” he mentioned. “Now, lastly, we are using chemistry.”