revealed the mystery of their origin. With important consequences for the production of precious metals in the universe

Professor Eleonora Troja, astrophysicist in Department of Physics at the University of Rome “Tor Vergata” and engaged in important studies of gamma-ray bursts (GRBS, gamma-ray bursts), together with an international group of researchers, have discovered that by finding the ‘home’ of the neutron stars that produced the GRBs, hitherto considered solitary, it is possible to put time onchemical evolution of the universe – thanks to which heavy metals such as gold, platinum and uranium were produced – so much so that it dates back to the first 5 billion years from its birth.

A significant number of gamma-ray bursts appear as solitary explosions, with no ‘galactic home’ to house them, raising questions about their true origins and distances.

Using data from some of the most powerful telescopes on Earth and in space, including Gemini twin telescopes and Hubble Space Telescopeastronomers have finally found their elusive ‘home’: a population of distant galaxies seen when the universe was only 5 billion years old.

The teacher Eleanor Troya few months ago associated with the physics department of the University of Rome “Tor Vergata” – after working for years at the NASA Goddard Space Flight Center – and co-author of the research on GRBs published in the latest issue (July 2022) of Monthly Notices of the Royal Astronomical Society, was awarded the “Exceptional Scientific Achievement” medal in 2021 precisely for the results obtained in the studies of short-lived gamma-ray bursts and kilonovae. And in 2020 she was awarded an ERC grant, which she brought to our university in Italy.

His studies were fundamental for the reconstruction of the chemical evolution of the universe: “We understood that the population of short GRBs (lasting less than 2 seconds) in the young universe is much more numerous than previously calculated – says Professor Troja – These new data tell us that neutron stars have merged in the history of the universe much faster than expected.”

Thanks to the powerful telescopes on Earth and in space, astronomers have been able to identify homes for neutron stars that were originally thought to be homeless. Their origin was not clear: “An intriguing mystery”, Professor Troja tells us “with two possible solutions proposed by astronomers to explain them: wandering stars or distant galaxies”. Instead now “We know the houses of GRBs well, they are large and bright galaxies, often quite close to us. Yet in many cases we see these gamma ray bursts happening in the middle of nowhere”.

The study began with a collaboration between NASA, Italy and the United Kingdom with data collected by Neil Gehrels’ Swift satellite, which captured more than 100 gamma-ray bursts, the effect of neutron stars (born from catastrophic supernova explosions). however, do not roam the galaxy because they are fired from their homes, but are so far away that they have not been seen before.

“For the future, breakthrough technologies such as the James Webb Space Telescope will allow us to identify and observe more and more precisely,” he explains. Brendan O’Connor, first author of the study, and a former student of Prof. Troy at the University of Maryland and George Washington University.

We can therefore confirm thatThe young universe was much richer in metals than previously thought. “These star castings are powerful forges of metals, not only precious like gold, but also those necessary for life, such as iodine“Concludes Troy” Finding them in such distant galaxies reveals that they have influenced the chemical evolution of the universe since its youth.


Images and videos: International Gemini Observatory / NOIRLab / NSF / AURA / J. da Silva / Fermilab
Image processing: M. Zamani (NSF’s NOIRLab) & D. de Martin (NSF’s NOIRLab)
Music: Stellardrone – In Time

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