One-armed spiral instability in neutron star mergers and its detectability in gravitational waves
One-armed spiral instability in neutron star mergers and its detectability in gravitational waves
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DOI：
10.1103/physrevd.94.064011
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发表时间：
2016-03
影响因子：
5
通讯作者：
D. Radice;S. Bernuzzi;C. Ott
中科院分区：
文献类型：
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作者：
D. Radice;S. Bernuzzi;C. Ott
利用高分辨率长期数值相对论模拟方法，研究了双中子星合并遗迹中m=1单臂螺旋不稳定性的发展和饱和。我们的结果表明，这种不稳定性是中子星合并在天体物理相关构型中的一般结果，包括“刚性”和“软”核态方程。我们发现，一旦在合并时播种，m=1模在∼10ms内饱和，并在长期时间尺度上持续。由m=1不稳定性发出的引力波的峰值频率在1-2 kHz左右，如果探测到，它们可以用来约束中子星的状态方程。我们通过将我们的高分辨率数值数据与包括潮汐效应在内的最先进的有效一体波形相结合，构建了跨越整个Advanced LIGO频段的混合波形。我们使用完全混合波形研究了Advanced LIGO和爱因斯坦望远镜的单臂螺旋不稳定性的可探测性。我们得出结论，单臂螺旋不稳定性不是一个有效的引力波发射体。即使在非常乐观的假设下，高级LIGO也只能探测到∼3Mpc以下的单臂不稳定性，这对应于10^(−7)yr^(−1)到10^(−4)yr^(−1)的事件率。可能需要第三代或更好的探测器来观察单臂不稳定性。
We study the development and saturation of the m=1 one-armed spiral instability in remnants of binary neutron star mergers by means of high-resolution long-term numerical relativity simulations. Our results suggest that this instability is a generic outcome of neutron star mergers in astrophysically relevant configurations, including both “stiff” and “soft” nuclear equations of state. We find that, once seeded at merger, the m=1 mode saturates within ∼10 ms and persists over secular time scales. Gravitational waves emitted by the m=1 instability have a peak frequency around 1–2 kHz and, if detected, they could be used to constrain the equation of state of neutron stars. We construct hybrid waveforms spanning the entire Advanced LIGO band by combining our high-resolution numerical data with state-of-the-art effective-one-body waveforms including tidal effects. We use the complete hybrid waveforms to study the detectability of the one-armed spiral instability for both Advanced LIGO and the Einstein Telescope. We conclude that the one-armed spiral instability is not an efficient gravitational wave emitter. Even under very optimistic assumptions, Advanced LIGO will only be able to detect the one-armed instability up to ∼3 Mpc, which corresponds to an event rate of 10^(−7) yr^(−1) to 10^(−4) yr^(−1). Third-generation detectors or better will likely be required to observe the one-armed instability.