In the realm of astrophysics and gravitational wave research, a team of scientists from the University of Barcelona and the University of California, Santa Cruz, has been delving into the intricacies of binary neutron star mergers. The researchers, Alberto Revilla Peña, Ruxandra Bondarescu, Andrew P. Lundgren, and Jordi Miralda-Escudé, have recently published their findings in the journal Physical Review D.
The team’s work focuses on the detectability of low-lying dynamical tides in binary neutron star or neutron star black hole mergers. These tides can excite oscillatory modes in one or both of the stars when the orbital frequency of the binary system sweeps through the resonant mode frequency. This process dissipates energy into the vibrational mode, causing a time advance in the merger and an excess phase. Both of these effects can cause a mismatch when fitting to a system that has not gone through the resonance.
To quantify this effect, the researchers computed the mismatch for current and planned detectors using two methods: a quasi-analytical approach that relies on the computation of moment integrals and an optimized version of the standard numerical match function. They found that detectability can occur for time advances of the order of 1 millisecond with advanced LIGO, Virgo, and KAGRA (LVK) detectors for an excess energy-flux that is a few percent of the gravitational wave emission.
The study’s results contrast with previous work, which modeled this effect solely as a phase shift of the waveform or by using the difference in the number of cycles induced by the resonant behavior. The researchers showed that tidal resonance effects primarily cause a time advance of the merger, rather than a phase difference. Additionally, they found that the single-frequency approximation commonly used in the literature significantly overestimates the detectability of this effect.
For the energy sector, particularly in the realm of gravitational wave energy harvesting, this research underscores the importance of accurate modeling and detection of these complex astrophysical phenomena. Understanding the nuances of binary neutron star mergers can help inform the development of technologies that harness the immense energy released during these events. The practical applications of this research extend to improving the sensitivity and accuracy of gravitational wave detectors, which are crucial for advancing our knowledge of the universe and potentially unlocking new energy sources.
Source: Physical Review D
This article is based on research available at arXiv.