Simulation of the orbits three interconnected black holes. The overview is shown in the left image. Zoomed in on the right-hand side. The red and blue black holes merge. Credit: Boekholt et al.
Arend Moerman, a Dutch student at Leiden University in the Netherlands, has successfully defended his thesis on the simulation of chaotic interaction of three black holes. He performed the simulations with Oxford and Leiden researchers. They found that heavier black holes tend to slingshot into space while lighter ones tend to merge. The results of the research will appear in the leading journal Physical Review D.
Arend Moerman, a Leiden master's candidate in astronomy, spent a whole year studying the dynamic interactions and collisions that occur between three imagined black holes. It is impossible to predict the interactions between three bodies, such as stars, planets, or black holes with an elegant formula. Moerman used a computer to calculate what happened for a brief period of time, and then use the results for the next period.
Extended with theory of relativity
The computer code is an extended version of a code that was used by Tjarda Bolkholt (University of Oxford), and Simon Portegies Zwart, co-author (Leiden Observatory Leiden University) in 2020, 2018. The extended code incorporates Einstein's theory on relativity. This is significant because Einstein's theory of relativity plays an important role in cases involving heavy objects like black holes.
Researchers varied the mass of the three black holes that interact with each other. They began with one solar mass, and increased it to a billion times that of the sun.
Tipping point
There appeared to be a tipping moment at around ten million solar mass. Simulations showed that black holes with masses less than ten million solar mass eject one another through a gravitational spiral slingshot. Black holes with masses greater than ten million solar mass merge. First, two black holes merge. The third black hole will come later. Black holes merge when they lose kinetic energie and emit gravitational waves.
Simon Portegies Zwart says that "Arend’s work" has led to a new understanding about how black holes can become supermassive. Simulations show that black holes that are large enough can collide almost instantly, and that they no longer move around in an endless manner.
Moerman was awarded the highest mark possible for his master's thesis. He has also started a second graduate research project about DESHIMA (a Dutch-Japanese microspectroscope).
Continue reading to learn more about how to detect merging dark holes and gravitational waves
Further information: Tjarda, C. N. Boekholt, Relativistic Pythagorean Three-Body Problem, Physical Review D (2021). Information for Journal: Physical Review D Tjarda C. N. Boekholt and colleagues, Relativistic Pythagorean 3-body problem, (2021). DOI: 10.1103/PhysRevD.104.083020
