What is a kilonova whose remains have just been revealed for the first time?

Discovered on August 17, 2017 in being NGC 4993 via Tools Puzzle Games and the Bakr (two interferometers are designed to detect) gravitational waves† GW170817 It is a reference attributed to the direct realization ofgravitational waves†Described as oscillations in curvature emptiness Albert predicted the propagation of gravitational waves from a source Einstein As early as 1916, it took nearly a hundred years for the first observation of gravitational waves to be made, in September 2015.

Unique Signal

according to astrophysicistCould this signal be issued yet? merger between two neutron stars† But what makes it special is its discoveryElectromagnetic waves Related: This is the first time an astronomical phenomenon in the form of gravitational waves and light has been detected. In fact, a shivering Gamma (GRB170817A), associated with GW170817, is detected by: Fermi Gamma Ray Space Telescope Less than two seconds after the start of the gravitational wave signal.

Since then, nearly 70 observatories, on Earth or in space, have taken part in observing this phenomenon. The radio telescopes American custard And VLBA can detect waves, for example radio Residues associated with GW170817, confirming the A. merger two neutron stars†

Kilonova is associated with this phenomenon

The AT 2017gfo event was detected about 11 hours after gravitational waves were observed kilonova (It can be defined as a file Supernova under the light). Due to its spatial and temporal proximity to GW170817, this kilonova was associated with the same neutron star merger. This phenomenon was accompanied by jets of rapidly moving charged particles. he moved Speed close light and production episode X-rays, measured by NASA’s Chandra Observatory. According to a team of American astrophysicists, the study of these X-rays could hold the key to identifying the object resulting from the merger of these two neutron stars.

Shortly after the discovery, X-rays are emitted from an aircraft Thing It will decrease little by little, while the flow of matter will slow down. But since 2020, this decline has occurred brightness They stop and give way to a relatively steady X-ray. according to Astronomy scientistsThis then indicates the discovery of an additional object, other than the charged particle beam: a different X-ray source is therefore needed to explain these observations.

Aurora… or even a black hole?

According to astronomers, this new source of X-rays could come from a shock from the rapid expansion of debris from the merger between the two stars. This shock would have heated the surrounding material and thus would emit X-rays – a phenomenon that would then be associated with the Kilonova’s residual glow.

hypothesis Black hole It was also not excluded, since the material falling into this cosmic giant can generate X-rays in the same way, since the accompanying radiation should be much brighter.

To find the end of the story, the Astronomy scientists They will continue to observe GW170817, both in X-rays and radio waves: in the case of the remaining brightness of a kilonova, X-rays and radio waves are expected to increase in the coming months. On the other hand, if the emission of X-rays decreased and the emission of radio waves stopped, scientists would lean toward the formation scenario instead. Black hole (This would then be the lowest mass detected!).