Researchers observe the formation of a magnetar at 6.5 billion light years

A researcher from the University of Arkansas is part of a team of astronomers who have identified an explosion of x-ray emissions from a galaxy located at around 6 , 5 billion light years from Earth, which corresponds to the fusion of two neutron stars to form a magneton, a large neutron. star with an extremely powerful magnetic field. Based on this observation, the researchers were able to calculate that such mergers occur about 20 times a year in each region of a billion light-years cube.

The research team, which includes Bret Lehmer, an assistant professor of physics at the University of Arkansas, analyzed data from Chandra's NASA flagship telescope.

The Chandra Deep Field-South survey includes over 100 X-ray observations of a single area of ​​the sky over a period of more than 16 years in order to collect information on galaxies from the universe. Lehmer, who has worked with the observatory for 15 years, has collaborated with colleagues in China, Chile and the Netherlands, as well as Pennsylvania State University and the University of Nevada. The study was published in Nature.

A neutron star is a small, very dense star, averaging 12 miles in diameter. Neutron stars are formed by the collapse of a star massive enough to produce a supernova, but not enough to become a black hole. When two neutron stars merge to become a magnetar, the resulting magnetic field is 10 trillion times more powerful than a kitchen magnet.

"Neutron stars are mysterious because the material they contain is extremely dense and unlike anything that can be reproduced in a laboratory," explained Lehmer. "We do not yet fully understand the physical state of neutron stars.Mergers involving neutron stars produce many unique data that give us clues about the very nature of neutron stars and what happens when They collide. "

An earlier discovery of the fusion of two neutron stars, which used gravitational waves and gamma rays to perform the observation, allowed astronomers to better understand these objects. The research team used this new information to search Chandra Observatory X-ray data for models consistent with what they learned about the fusion of neutron stars.

The researchers discovered an X-ray explosion in the Chandra Deep Field-South survey data. After excluding other possible sources of X-rays, they determined that the signals came from the process of forming two magnetron-forming neutron stars.

"Essential proof is how the signal has changed over time," said Lehmer. "Its brilliant phase has reached a plateau and then dropped in a very specific way.It is exactly what one would expect from a magnetar that quickly loses its magnetic field under the effect of radiation. "

Similar calculations for the neutron star melting rate have been made on the basis of fusions detected by gravitational waves and gamma rays, reinforcing the case for using X-ray data to detect such exotic fusion events in the universe.