Neutron star explosions may have caused gold to form, new study suggests

The true origins of the Earth’s heaviest elements like gold have eluded astrophysicists for decades. The prevailing scientific view is that neutron star collisions created gold and other heavy elements, but one study has now pointed to another tantalizing theory behind the metals’ formation.According to the study published last week in The Astrophysical Journal Letters, it is explosions of highly magnetized neutron stars, or magnetars, that caused gold and other heavy metals to form in space.The conclusion follows an analysis of 20-year-old archival data from NASA and European Space Agency, which showed that the magnetars, when undergoing a seismic event similar to an earthquake, can unleash giant flares, a rare explosive event that releases high-radiation gamma rays. The researchers found that during such events, the magnetars would unleash material into the universe, though they could not definitively explain the ejection of the star’s mass.“It’s a pretty fundamental question in terms of the origin of complex matter in the universe,” said Anirudh Patel, a doctoral student at Columbia University in New York, as quoted in an article published on the NASA website. “It’s a fun puzzle that hasn’t actually been solved.”Possible explanationThe answer, according to Patel and colleagues, including his advisor Brian Metzger, professor at Columbia University and senior research scientist at the Flatiron Institute in New York, may lie in the atomic structure of elements. The formation of gold and other heavy metals could have happened through a “rapid process” of neutrons forging lighter atomic nuclei into heavier ones, the authors said.Sometimes when an atom captures an extra neutron, the atom becomes unstable and a nuclear decay process happens that converts a neutron into a proton, moving the atom forward on the periodic table. This is how, for example, a gold atom could take on an extra neutron and then transform into mercury, they wrote.Recent research by co-authors of the study — Jakub Cehula of Charles University in Prague, Todd Thompson of The Ohio State University, and Metzger — has found that magnetar flares can heat and eject neutron star crustal material at high speeds, making them a potential source.Early-universe eventBefore this study, the formation of heavy elements such as gold was attributed only to neutron star collisions, or kilonovas. When astronomers observed a neutron star collision in 2017 through telescopes, they found the event could create heavy elements such as gold, platinum and lead. However, these collisions, most of which occurred in the past several billion years, are believed to have happened too late in the universe’s history to explain the earliest gold.Scientists have theorized that lighter elements such as hydrogen and helium, and even a small amount of lithium, likely existed early on after the Big Bang created the universe 13.8 billion years ago. Later, some heavier elements, including iron, were forged in stars, but the formation of elements heavier than iron, like gold, remained a mystery.Astronomers have suggested that the first magnetars were formed after the first stars about 13.6 billion years ago, which was earlier than the Big Bang event, according to the study’s co-author Eric Burns, assistant professor and astrophysicist at Louisiana State University in Baton Rouge.In the NASA’s publication, it is expected that its forthcoming COSI (Compton Spectrometer and Imager) mission will follow up on these results. A wide-field gamma ray telescope, COSI is expected to launch in 2027 and study energetic phenomena in the cosmos, such as magnetar giant flares.Weiter zum vollständigen Artikel bei Mining.com Weiter zum vollständigen Artikel bei Mining.com