The Limited Times

Now you can see non-English news...

A cosmic flash never seen, has the glow of gold

2022-12-08T13:46:38.530Z


A cosmic flash never seen, the closest and most lasting ever observed and the brightest, made so bright by two incredibly dense stars which, merging, have generated gold, platinum and uranium: it is enough to ignite the enthusiasm of astronomers because now the origin of these violent cosmic events is a little less mysterious. (HANDLE)


A cosmic flash never seen, the closest and most lasting ever observed and the brightest, made so bright by two incredibly dense stars that, merging, have generated gold, platinum and uranium: it is enough to ignite the enthusiasm of astronomers because now the origin of these violent cosmic events is a little less mysterious.

The discovery is described by four articles published in the journal Nature, two of which are signed by Italians: one article has Eleonora Troja, from the University of Rome Tor Vergata, as its first author, and another article has Alessio Mei, from the Gran Sasso Science Institute (Gssi) in L'Aquila.

A third paper has lead author Jillian Ratinejad of Northwestern University, and a fourth has lead author Jun Yang of China's Nanjing University.



It's a story that began a billion years ago, outside our galaxy, when two neutron stars, in which matter has a very high density, danced around each other until they merged and emitted a long gamma-ray signal .

The first to capture it was NASA's Swift Space Telescope.

The gamma-ray burst, called GRB211211A, was observed on December 11, 2021 and it was thought that this, like the others observed up to then, was generated by a dying star that exploded in a supernova.

Further data collected by Earth-based telescopes and the Fermi Space Telescope, with its Lat instrument, of the National Institute of Nuclear Physics (Infn) suggested it was something else.

Finally the discovery that to trigger the

event was a kilonova, i.e. the merger of two neutron stars located over a billion light-years from us.

"Astronomically speaking, almost around the corner," according to the researchers.

Artist's impression of the gamma-ray burst 211211A, centered on the kilonova (source: Aaron Geller/Northwestern/CIERA and IT Research Computing Services)



"The GRB211211A event showed a bright flux of high-energy gamma rays several minutes after the two neutron stars merged and lasted for several hours," Mei says.

She expected the gamma-ray burst to weaken over time, "but to our surprise, the flux remained constant for a long time."

Even the light observed in the visible and infrared wavelengths "was very different from what would be expected" if the flash had been caused by the death of a star and its explosion in a supernova.

It was, in fact, the "radioactive glow caused by the production of heavy metals such as gold, platinum and uranium", observes Elisabetta Troja,

returned to Italy from the United States thanks to a grant from the European Research Council (ERC) and her third article in Nature in 5 years.

"We were able to observe this kilonova because it was really close to us. It is very rare - she adds - to detect such powerful explosions in galaxies close to us and every time we learn something more about the Universe".



Thus begins a new research adventure: for one of the protagonists of the discovery of gravitational waves, Marica Branchesi, of Gssi and associated with Infn, "this discovery opens up new fascinating scenarios in multi-messenger astronomy", astronomy that uses signals of different kinds as cosmic messengers.

Source: ansa

All tech articles on 2022-12-08

You may like

Trends 24h

Latest

© Communities 2019 - Privacy

The information on this site is from external sources that are not under our control.
The inclusion of any links does not necessarily imply a recommendation or endorse the views expressed within them.