[Submitted on 27 Feb 2026] (cross-list from astro-ph.HE)
Realistic Equations of State Informing Neutron Star Post-Merger Gravitational-Wave Frequencies
Spencer J. Magnall🇦🇺 · Nilaksha Barman🇮🇳 · Debarati Chatterjee🇮🇳 · Paul D. Lasky🇦🇺 · Simon Goode🇦🇺
Binary neutron star mergers are thought to produce hot, rapidly rotating neutron stars with masses that can far exceed their Tolman-Oppenheimer-Volkoff mass. The gravitational-wave emission from such remnants provides a unique opportunity to measure the nuclear equation of state at densities and temperatures not available to terrestrial experiments. Current detector design is informed by gravitational-wave signals from general relativistic hydrodynamics simulations of neutron star mergers, typically with hybrid thermal treatments for the equation of state, where a cold equation of state is modified by adding a thermal component. We use realistic equations of state based on the relativistic mean field model with consistent treatment of thermal effects to compute the distribution of expected peak gravitational-wave frequencies. Marginalising over equation of state and progenitor neutron star masses, we show the peak frequency of emission ranges from to 4 kHz. The width of this distribution suggests the need for broadband observatories with kHz sensitivity, and calls into question some of the so-called post-merger optimised configurations. We show the proposed KAGRA high-frequency design is well-suited to measuring post-merger remnants when compared to the KAGRA broadband design.
- Comments:
- 8 pages, 5 figures, to be submitted
- Subjects:
- High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc); Nuclear Theory (nucl-th)
- arXiv:
- 2602.23646 [pdf]