Ancient, Primordial Stars May Have Left No Trace Behind After Dying in Explosion
It turns out that some ancient, primordial stars die in an unusual way. While most stars leave behind a remnant or black hole, certain ancient, large stars may have exploded as supernovae and then burned out completely, leaving no trace behind.
First-generation stars, the stars that were the first to form in our universe, produced the first heavy elements, or chemical elements other than hydrogen and helium. After dying, these old stars sent these chemicals into space, which paved the way for subsequent generations of stars.
In order to learn a bit more about these first-generation stars, the researchers ran a number of supercomputer simulations. They relied on CASTRO, a compressible astrophysics code. The researchers found that most primordial stars between 55,000 and 56,000 solar masses lived about 1.69 million years before becoming unstable and beginning to collapse. As the star collapsed, it began to rapidly synthesize heavy elements. This process released more energy than the binding energy of the star, holding the collapse and causing an explosion. Yet what was interesting was what happened after the explosion.
"We found that there is a narrow window where supermassive stars could explode completely instead of becoming a supermassive black hole-no one has ever found this mechanism before," said Ke-Jung Chen, one of the researchers, in a news release.
Depending on the intensity of the supernova, these stars could enrich their entire host galaxy with elements as they explode. In some cases, the supernova could even trigger a burst of star formation in the galaxy.
The findings reveal a bit more about these supermassive, ancient stars and show how they may have interacted in the past.
The findings are published in The Astrophysical Journal.