Pratten Geraint, Schmidt Patricia, Williams Natalie
School of Physics and Astronomy and Institute for Gravitational Wave Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom.
Phys Rev Lett. 2022 Aug 19;129(8):081102. doi: 10.1103/PhysRevLett.129.081102.
Gravitational waves (GWs) from inspiraling neutron stars afford us a unique opportunity to infer the as-of-yet unknown equation of state of cold hadronic matter at supranuclear densities. During the inspiral, the dominant matter effects arise due to the star's response to their companion's tidal field, leaving a characteristic imprint in the emitted GW signal. This unique signature allows us to constrain the cold neutron star equation of state. At GW frequencies above ≳800 Hz, however, subdominant tidal effects known as dynamical tides become important. In this Letter, we demonstrate that neglecting dynamical tidal effects associated with the fundamental (f) mode leads to large systematic biases in the measured tidal deformability of the stars and hence in the inferred neutron star equation of state. Importantly, we find that f-mode dynamical tides will already be relevant for Advanced LIGO's and Virgo's fifth observing run (∼2025)-neglecting dynamical tides can lead to errors on the neutron radius of O(1 km), with dramatic implications for the measurement of the equation of state. Our results demonstrate that the accurate modeling of subdominant tidal effects beyond the adiabatic limit will be crucial to perform accurate measurements of the neutron star equation of state in upcoming GW observations.
来自相互绕转中子星的引力波（GWs）为我们提供了一个独特的机会，来推断超核密度下冷强子物质尚未知晓的状态方程。在相互绕转过程中，主要的物质效应源于恒星对其伴星潮汐场的响应，在发出的引力波信号中留下特征印记。这种独特的特征使我们能够限制冷中子星的状态方程。然而，在引力波频率高于≳800 Hz时，被称为动态潮汐的次要潮汐效应变得重要起来。在本信函中，我们证明忽略与基模（f模）相关的动态潮汐效应会导致在测量恒星的潮汐形变能力以及由此推断的中子星状态方程时产生很大的系统偏差。重要的是，我们发现f模动态潮汐在先进激光干涉引力波天文台（Advanced LIGO）和处女座（Virgo）的第五次观测运行（约2025年）时就会产生影响——忽略动态潮汐会导致中子半径出现O(1 km)量级的误差，这对状态方程的测量有重大影响。我们的结果表明，在即将到来的引力波观测中，对绝热极限之外次要潮汐效应进行精确建模对于准确测量中子星状态方程至关重要。
