According to recent research, the early universe’s neutron star mergers are the source of strong and enigmatic radiation bursts.
A neutron star merger that produced gamma rays in the early cosmos is seen in an illustration. Two powerful material-filled jets are being released into space by a white star with a blue ring around it.
A neutron star merger that produced gamma rays in the early cosmos is seen in an illustration. (Photo credit: J. da Silva/Spaceengine/NOIRLab/NSF/AURA)
It may be possible for extremely faint galaxies that are located up to 10 billion light-years away to be the cause of inexplicable isolated bursts of strong energy that previously could not be linked to galactic origins.
These “castaway” brief gamma-ray bursts were traced to extremely far-off galaxies by a worldwide team of astronomers using some of the most potent ground- and space-based observatories, such as the Gemini North telescope in Hawai’i and the Gemini South telescope in Chile.
Brendan O’Connor, an astronomer from the Universities of Maryland and Washington, D.C., said in a statement: “Many brief gamma-ray bursts are discovered in bright galaxies quite close to us, but some of them appear to have no corresponding galactic home.”
(new tab opens) We were able to go through vast amounts of data from observatories like the twin Gemini telescopes and identify the faint glimmer of galaxies that were previously too far away to be noticed by their brief gamma-ray bursts by determining their origin.
The results suggest that gamma-ray bursts, which are produced when very compact collapsed stars called neutron stars meet and combine, may have been more frequent than previously thought.
This suggests that the early galaxies may have been richer in precious metals than currently projected. This is because it is thought that these mergers trigger cascades of nuclear fusion processes that forge heavier atoms and metals like gold and platinum.
Before beginning their investigation, O’Conner and his colleagues looked over information pertaining to 120 gamma-ray bursts recorded by two detectors on NASA’s Neil Gehrels Swift Observatory.
The observatory’s X-ray Telescope utilizes the gamma-ray burst’s X-ray afterglow to pinpoint the burst’s position after Swift’s Burst Alert Telescope notices it. The Lowell Observatory then determines more precise locations for the gamma-ray bursts.
43 brief gamma-ray bursts that appear to have originated from relatively empty interstellar space rather than from a galaxy have been discovered through studies of these afterglows.
A detailed image of space reveals a large number of far-off stars and galaxies, including a previously unnoticed faint and far-off galaxy that is considered to be the source of a potent gamma-ray burst.
A strong gamma-ray burst has its source in a newly undiscovered faint and distant galaxy. (Image credit: NOIRLab/NSF/AURA/International Gemini Observatory)
Astronomers have come up with two theories to explain why these hostless gamma-ray bursts appeared to exist in isolation, O’Conner said.
The colliding neutron stars are thought to have formed as a binary pair in a distant galaxy and subsequently drifted together into interstellar space, according to one theory put up to explain this riddle. After many billions of years, they finally combine.
Another hypothesis, which O’Connor and his coworkers concentrated on investigating, is that the neutron star mergers that produced these solitary gamma-ray bursts took place over a very long period of time, when the universe was only around 3.8 billion years old. From our vantage point on Earth, the origin galaxies now seem quite dim because to their tremendous distance.
According to O’Connor, “We felt that this second scenario was the most likely to account for a significant portion of hostless occurrences.” The most powerful telescopes on Earth were then utilized to gather detailed photographs of the gamma-ray burst sites, which revealed hitherto undiscovered galaxies 8 to 10 billion light-years from Earth.
The most massive neutron star ever seen is destroying its partner.
A Gamma-Ray Burst: What Is It?
— Gamma-ray bursts don’t move about much.
The 8.1-meter twin Gemini telescopes were chosen by the researchers because they can cover the whole sky thanks to their positions in opposing hemispheres, which is necessary for gamma-ray burst research. Out of the 31 transient gamma-ray bursts they examined, the crew was able to identify the source for 17 of them using the Gemini data.
The results may assist astronomers in their quest to comprehend the chemical development of the cosmos, as well as provide a solution to the castaway gamma-ray burst enigma.
This advances the date of when the cosmos acquired the “Midas touch” and started to accumulate the heaviest elements listed on the periodic table, according to O’Connor.
The team’s research is published on the online preprint repository ArXiv.