Reinier Jonker, PhD at Nikhef, will defend his thesis Monday 27 oktober 2025 at 13.00 at the Amsterdam University.
“Applying Polynomial Search: Searching for Gravitational Waves from Neutron Stars in Binary Systems in O3b Strain Data and the Sco X-1 Pipeline Comparison”
“It follows from Albert Einstein’s General Theory of Relativity that rotating objects can cause propagating waves in gravity. Brief gravitational wave events have been observed over 200 times from the mergers of black holes and/or neutron stars, two types of remnants of heavy stars, into one new object. This requires advanced specialised observatories, such as Virgo, LIGO and KAGRA, but also accurate models of possible signals.
It has also been proposed that neutron stars in binary systems can continuously generate weaker gravitational waves that might also be detectable by these observatories if the period of observation is long enough and if a sufficiently accurate model of the signal is available.
While it is likely that there are many neutron stars, detailed knowledge of the characteristics of a neutron star is needed to accurately model its expected signal shape, which is only available when it has been observed with telescopes. Most likely, this is only possible for a small fraction.
An alternative to searching for a specific neutron star binary system would be to match a great number of signal templates against the data, covering a large fraction of possible signals. Unfortunately, modelling all possible signals explicitly would take far too much computation time, so a method is required that yields a good approximation of many possible signals with a feasible number of signal templates.
This thesis described an approach called Polynomial Search, originally devised by Henk Jan Bulten and Sipho van der Putten and further developed over the course of this research. It presents results for an analysis on three days of data from the Virgo gravitational wave observatory in Cascina, Italy, and a comparison with other analysis methods for simulated signals from a binary neutron system called Sco X-1.”
“Applying Polynomial Search: Searching for Gravitational Waves from Neutron Stars in Binary Systems in O3b Strain Data and the Sco X-1 Pipeline Comparison”
The PhD defense will take place in the Agnietenkapel, Oudezijds Voorburgwal 229 – 231, 1012 EZ Amsterdam.
More information and link to the livestream on the website of the UvA.
Supervisor: prof. dr. F.L. Linde
Co-supervisor: dr. H.J. Bulten
Contact: Reinier Jonker
