The first supernovas of the universe probably produced water

The first band of stars in the universe could have produced significant amounts of water after their death, only 100 million to 200 million years after the Big Bang.

Water signatures were previously observed about 780 million years after the Big Bang. But now, computer simulations suggest that this essential state of life existed much earlier than astronomers thought, researchers report on March 3 Astronomy of nature.

“The surprise was that the ingredients for life were all in the dense cloud cores [leftover after stellar deaths] So early after the Big Bang, ”says astrophysicist Daniel Whalen of the University of Portsmouth in England.

Water can be common today. But at the beginning, approximately 13.8 billion years ago, the universe was essentially only hydrogen, helium and little lithium. It took stars to make the rest. Some middle -weight elements, such as carbon and oxygen, are melted inside the stars while aging. Others are forged in stellar deaths, such as explosive supernovas or violent unions of neutron stars. However, to form more complex molecules in considerable quantities, relatively dense and cold conditions are needed, ideally less than a few thousand degrees Celsius, are needed.

“Water is a very fragile molecule,” says astronomer Volker Brom of the University of Texas in Austin, which was not involved in new research. “So catching is, do we have conditions that can form it [very early in the universe]? “

To see if there could be water in the juvenile universe, Whalen and his colleagues led computer simulations of life and deaths of two first -generation stars. Because astronomers think that early stars were much larger and had shorter longevity than modern stars, the team simulated a star with 13 times more sun and 200 times another mass of the sun. At the end of their short lives, these behemoths explode as supernova and explode an element shower, including oxygen and hydrogen.

Simulations showed that while the expelled supernova material expanded and cooled, oxygen reacted with hydrogen and dihydrogen, or two hydrogen atoms, to make water steam in Halos growing waste.

This chemical process continued slowly, as the density of atoms in the external regions of the expansion supernova explosions was low. This low density means that it is unlikely that two elements would meet and connect to short time limits.

But after a few million years – or tens of millions of years in the case of the smallest star – the central nucleus of supernova residual dust had cooled enough to form the water. The water began to accumulate rapidly there as the density was high enough to meet the atoms.

“[The water’s] Focusing on dense structures, that for me is changing the game, ”says Whalen. “The total total mass of water being formed is not so much. But it really becomes concentrated in dense nuclei, and dense nuclei are the most interesting structures in residues, because new stars and planets can be formed here. “

At the end of the simulations, the smallest supernova produced a mass of water equivalent to one -third of the total mass of the soil while the largest created enough water to equate 330 soils. In principle, Whalen says, if a planet were to be formed on a essential waste from the largest supernova, it could be a water world like ours.

“There seems to be an indication that the universe as a whole may have been habitable, if you like it, already too early,” Bromm says. But the water does not take you to life, he adds. “Then start asking the question, [how early] Can you combine carbon with hydrogen to get life molecules? “