Scientists first saw microwave radiation during the merger of neutron stars

Scientists first saw microwave radiation during the merger of neutron stars

An international group of scientists, using the ALMA telescope, detected high-frequency radiation from a short gamma flash of GRB 211106A. This explosion was formed by merging neutron stars 20 billion light years from the Earth.

The light from this short-term gamma flash was so weak that while NASA's early X-ray observations saw an explosion, the host galaxy was not detected at this wave length, and scientists were unable to determine exactly where it came from. The unprecedented sensitivity of the ALMA telescope helped scientists record a millimetre radiation and adjust the location of the source of the explosion.

ALMA's unprecedented sensitivity allowed us to determine more accurately the location of the gamma flash in this field, and it ended up in another weak galaxy that is further away, which means that this short-term gamma flash is even more powerful than we thought at first, which makes it one of the brightest and most energetic observations ever made.

Gamma-rays are the brightest and most energetic explosions in the universe that can emit more energy in a few seconds than our Sun can emit in its lifetime. GRB 211106A is a short-term gamma-ray. Such events last only a few tenths of a second, but are thought to lead to the formation of heavy chemical elements, such as platinum and gold, as a result of a catastrophic merger of dual star systems containing a neutron star.

Under the gravitational waves of a star in dual systems, one of which is neutron-based, moves along a spiral to meet each other, explains astrophysics. After a collision, there's an explosion, followed by jets moving at a speed close to the speed of light. When one of these jeets targets the Earth, we see a short pulse of gamma radiation or a short-term gamma flash.

The short-term surge usually lasts only a few tenths of a second, then scientists look for the light, the light emitted by the jets interacting with the surrounding gas, but it's hard to detect them. Over the entire period of observation, less than ten short gamma flashes have been detected in the radio band, and this explosion was the first to be seen in a millimetre range of waves.

Image on the cover: an artistic image of the merger of stars and after-lighting.