Leiden student of astronomy receives rare 10 for thesis | Inland

Because interactions between three bodies such as stars, planets or black holes cannot be predicted with an elegant formula, Moerman used a computer that always calculated what happened for a short time and then used that outcome for the next period of time. In this way computers also make weather forecasts.

The simulations show that lighter black holes usually throw each other away, while heavier black holes mainly merge. Black holes that are lighter than about 10 million solar masses usually throw each other away in the simulations. Black holes that are heavier than about 10 million solar masses are merging. First two, later the third black hole follows. This merger is because the black holes lose kinetic energy and that in turn is because they emit gravitational waves.

Portegies Zwart is proud of his pupil, who he describes as a smart bird. “Moerman’s research, which lasted a year, has an eye for detail, is independent, and has yielded a scientifically interesting result. Moreover, he is also a down-to-earth and modest boy,” said the professor.

Moerman was looking for a graduation topic at the interface of astronomy, mathematics and computer science. Supervisor Portegies Zwart offered him the opportunity for this combination. “Programming attracted me,” Moerman says on the site of his university. “At first it wasn’t quite clear what to do. I had to build the theory of relativity into an existing code, but how and what was not yet determined. But that was what made it fun: it gave me the freedom to find what I found interesting and to simulate that.”

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