A study led by a team of astrophysicists, including Syracuse University Professor Eric Coughlin, confirmed the accuracy of their detailed model by observing the dimming of a light source located 860 million light-years away. They used powerful telescopes like NASA’s Hubble, James Webb, and Chandra X-ray Observatory to study tidal disruption events (TDEs) where a star is destroyed by a supermassive black hole, leading to a luminous accretion flare that allows scientists to study black holes at cosmological distances. By analyzing the brightening and dimming of the source, the team was able to probe the physics of black holes and provide new insights into these extreme cosmic environments.
TDEs occur when a star is torn apart by a black hole’s immense gravitational field, creating a stream of debris that forms a bright accretion disk around the black hole. By making direct observations of TDEs and comparing them to theoretical models, scientists can relate observations to the physical properties of disrupted stars and their disrupting black holes. The team of physicists from Syracuse University, MIT, and the Space Telescope Science Institute used detailed modeling to predict the dimming of AT2018fyk, a repeating partial TDE where the core of the star survived multiple interactions with the supermassive black hole. This prediction was confirmed when the source dimmed in August 2023, validating their model and providing a new method for studying black holes.
Extragalactic surveys conducted by telescopes like Chandra allow scientists to monitor a wide range of light sources in deep space, detecting sudden brightening or dimming events that indicate changes in the cosmos. Telescopes that can observe the X-ray spectrum emitted by extremely hot materials play a crucial role in this research, as they provide insights into the physics of black holes and other high-energy sources. The hottest gas in an accretion disk emits X-rays, which have higher energy and shorter wavelengths than visible light, making it possible for telescopes like Chandra to study distant galaxies and black holes.
A team of physicists, led by Professor Coughlin and including researchers from MIT and the Space Telescope Science Institute, published a paper detailing a model for a repeating partial TDE known as AT2018fyk. By studying the return orbit of a star around a supermassive black hole, the team uncovered new information about these extreme cosmic environments. AT2018fyk was initially observed in 2018, located 870 million light-years away, and the team used a trio of telescopes to make detections and predictions about its behavior. The star’s repeated interactions with the black hole led to the formation of a bright accretion disk that researchers could study using X-ray and Ultraviolet/Optical telescopes.
The team’s detailed model accurately predicted the disappearance of the light source in August 2023, followed by a brightening in 2025 when freshly stripped material accretes onto the black hole. The confirmation of this model through observed X-ray flux changes supports the idea that the star is being devoured by a massive black hole over time. The predicted orbital period of the star around the black hole and the expected rebrightening by 2025 offer valuable insights into the interaction between stars and black holes in the cosmos. By studying repeating partial TDEs like AT2018fyk, scientists can gain a better understanding of these rare events that occur once every million years in a galaxy.
The research team’s model provides a new approach to studying repeating partial TDEs and offers a promising tool for identifying and analyzing these occurrences in the future. With improved detection technology and the increasing ability to observe distant galaxies and black holes, researchers hope to uncover more systems exhibiting similar behaviors. The potential for further observations of these events, as well as the development of more accurate models, could lead to groundbreaking discoveries in the field of astrophysics and deepen our understanding of the universe’s most extreme phenomena.
