Tidal disruptions occur when a star passes too close to a supermassive black hole. The immense gravitational force of the black hole rips the star apart, forming a stream of debris that falls towards the black hole. MAXI J1820 is a particularly interesting case because it harbors an intermediate-mass black hole with a mass several hundred times that of the Sun, making it an ideal testbed for studying strong gravity.
Einstein's theory predicts that as matter falls into a black hole, it should emit X-rays and gamma rays due to the release of gravitational potential energy. The specific pattern and timing of these emissions depend on the characteristics of the black hole and the infalling matter.
Observations of MAXI J1820, obtained using facilities such as NASA's Neil Gehrels Swift Observatory, the European Space Agency's XMM-Newton satellite, and various ground-based telescopes, have revealed detailed light curves and spectra of the tidal disruption event. These observations match remarkably well with the theoretical predictions made by Einstein's general relativity.
The data shows a distinct peak in X-ray and gamma-ray emissions, known as the "primary peak," followed by a "plateau" phase and then a gradual decline in brightness. These features correspond to different stages of the tidal disruption process, where matter streams fall into the black hole, and the system evolves.
Furthermore, the observations reveal a strong correlation between the observed luminosity of the tidal disruption event and the mass of the black hole, as predicted by general relativity. This relationship supports the idea that the observed phenomena are indeed caused by the gravitational forces near a black hole.
The detailed study of MAXI J1820 has provided strong observational evidence supporting Einstein's general theory of relativity and our current understanding of how matter behaves in the extreme gravitational environment around black holes. It showcases the power of studying such extreme astrophysical events to deepen our knowledge of fundamental physics.
