Scientists may finally know why the first stars in the universe left no trace
The first stars of the universe may have been much smaller than we thought, new research clues-perhaps explaining why it is so difficult to find evidence that they have ever existed.
According to the new research, the first generation of stars had a difficult story. These stars have become in a violent environment: inside a huge cloud of gas whipping with turbulence at supersonic speed at speeds five times the speed of sound (as measured in the atmosphere of the earth).
A simulation that underpins new research has also shown that gases gathered in bumps and bumps which seemed to announce an upcoming star. The cloud has separated, creating pieces from which stars’ clusters seemed ready to emerge. A gas cloud has finally settled in the right conditions to form an eight -time star the mass of our sun – much smaller than the moaning of the 100 solar mass that researchers previously imagined in our first universe.
These results suggest that the first supergiring stars in history can have become in stellar networks – not in splendid isolation, as previously thought.
“With the presence of supersonic turbulence, the cloud fragments in several smaller clusters, leading to the formation of several less massive stars instead”, main researcher Ke-Jung ChenA researcher at the University Institute of Sinica of Astronomy and Astrophysics in Taiwan, told Livescience by e-mail.
This overview of our first story is crucial to learning the origins of our galaxy, as well as our solar system.
“These first stars played a crucial role in the formation of the first galaxies, which finally evolved into systems like our own Milky Way,” wrote Chen. With this new model in hand, he added, new observations can bring research further, by studying the Starbirth and the training of galaxies using IT models and NASA James Webb space telescope.
Simulation of the universe
Researchers have generated their new understanding of the first stars using the Gizmo simulation codewhich is used to study astronomical phenomena ranging from black holes to magnetic fields, and a project called illustristng which previously demonstrated accurately reproduce the formation of galaxy. Their objective was to study the conditions of our cosmos a few hundred million years after the Big Bang, 13.8 billion years ago.
In relation: Scientists just recreated the first molecules of the universe – and the results question our understanding of the first cosmos
Given the scale of the universe, the simulation has focused on a single area: a dense structure, about 10 million times the mass of our sun, called a minihalo of dark matter. (Dark matter Most of the stuff in our universe, but does not interact with light and cannot be detected by telescopes. However, we can deduce the presence of black matter through its gravitational effect on other objects.)
The researchers examined how gas particles moved to relatively small space regions inside the halo, each region measuring approximately three light years. The simulations have shown that minihalo dark matter attracts gas with pure gravity and, in doing so, generates both turbulence at supersonic speed and clouds of gas clouds. Violence was therefore part of the creation of early stars.
This traumatic environment has created another side effect: there were fewer huge stars than we imagined before. Previous research had suggested that we could have had early stars of more than 100 solar masses each. Finally, these old stars would have exploded like supernovas, leaving behind traceable remains that the new stars would incorporate as they grew.
The more recent stars, however, show no chemical signature of old giants inside – showing that a first generation of huge stars may have been rare.
The Chen team is not yet over. They now use the halos of dark matter to see how supersonic turbulence more generally worked in the universe at the beginning, especially since the first stars have proven in the era more than 13 billion years ago, called “cosmic dawn”.
“This article is part of an effort of collaboration aimed at understanding cosmic dawn by studying the training and evolution of the first stars,” said Chen.
The next set of simulations can also include magnetic fields, he added. We can see in galaxies today that supersonic turbulence stimulates magnetic fields and influences the formation of stars; Magnetism may be just as crucial for star training in the early universe.
Chen’s team published its results on July 30 in the journal Astrophysical newspaper letters.
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