A team of astronomers has detected, for the first time, the presence of fluorine in a galaxy called NGP-190387, more than 12,000 million light years from Earth . The finding is significant since fluorine is an element that we can find in our teeth and bones, and scientists believe that it would provide us with information about how fluorine is forged in the universe. This is the most distant detection of this chemical to date.
Chemicals are forged into the hearts of dying stars , which fuse heavier and heavier elements as hydrogen and helium are depleted before finally shedding their matter, forming a cloud of gas.
How have they managed to detect fluoride at such a far distance?
It really is a milestone. It has been detected at such an impressive distance, since the universe was barely 1,400 million years old – approximately 10% of the current age of the universe – using the Atacama Large Millimeter / submillimeter Array (ALMA) telescope located in Chile.
Since the galaxy was exceptionally bright, Franco and his collaborators were able to detect the faint radiation emitted billions of years ago by fluorine in NGP-190387. The reason for this glow was another massive galaxy located between it and Earth near the line of sight.
“Like most of the elements that surround us, fluorine is created in stars, but until now, we did not know exactly how this element was produced ,” commented Maximilien Franco, co-author of the work published in the journal Nature Astronomy.
Stars expel heavy elements towards the end of their lives, and this fluorine suggests that the stars that created it must have lived and died very quickly, according to the authors. In fact, they believe that Wolf-Rayet stars, very massive stars that live for only a few million years, are the most likely production sites for this element.
“We all know about fluoride because the toothpaste we use every day contains it in the form of fluoride,” says Franco. “Like most elements around us, fluorine is created inside stars, but until now, we didn’t know exactly how this element was produced. We didn’t even know what kinds of stars produced most of the fluorine in the universe! ! “.
Joking about the discovery, Franco stated: “We have shown that Wolf-Rayet stars, which are among the most massive stars known and can explode violently at the end of their lives, help us, in a way, to maintain a good dental health “ .
Previous explanations of the origin of fluorine included its production in pulsations of evolved giant stars with masses up to several times that of the Sun. They are known as asymptotic giant branch stars , but the authors believe that these scenarios might not fully explain the amount of fluorine in NGP-190387.
This is also one of the first times that fluorine has been seen beyond the Milky Way and neighboring galaxies.
Referencia: M. Franco, K. E. K. Coppin, J. E. Geach, C. Kobayashi, S. C. Chapman, C. Yang, E. González-Alfonso, J. S. Spilker, A. Cooray & M. J. Michałowski. The ramp-up of interstellar medium enrichment at z > 4. Nature Astronomy, 2021 DOI: 10.1038/s41550-021-01515-9
