Gravitational wave background from sub-luminous GRBs: prospects for second- and third-generation detectors
Gravitational wave background from sub-luminous GRBs: prospects for second- and third-generation detectors
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DOI：
10.1111/j.1365-2966.2010.17585.x
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发表时间：
2010-08
影响因子：
4.8
通讯作者：
E. Howell;T. Regimbau;A. Corsi;D. Coward;R. Burman
中科院分区：
文献类型：
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作者：
E. Howell;T. Regimbau;A. Corsi;D. Coward;R. Burman
我们评估了与亚发光伽马射线暴（SL-GRBs）相关的引力波背景的探测前景。我们假设这些爆发中有很大一部分的中心引擎是由新生的磁星提供的，并考虑了两种可能的GW发射机制。首先，一颗新生磁星的变形诱导的三轴GW发射。其次，长期条形不稳定性的开始，与在许多伽马射线爆发的x射线余辉中观察到的长寿命平台有关。在可探测性方面，我们发现长期不稳定的开始是最乐观的情况：假设与长期不稳定磁星相关的伽马射线暴以（48-80）Gpc^(−3)yr^（−1）或更大的速率发生，两台爱因斯坦望远镜（ETs）的数据相互关联可以在观测1年后以3或更大的信噪比探测到与该信号相关的GW背景。假设中子星的自旋下降纯粹是由三轴GW发射引起的，我们发现ET需要大约（130-350）Gpc^(−3)yr^（−1）的速率来探测由此产生的GW背景。我们表明，长期不稳定的背景信号可能潜在地掩盖在ET最敏感的频率范围内的原始GW背景信号。最后，我们展示了如何考虑宇宙金属丰度演化可以提高与sl - grb相关的背景信号的预测信噪比。
We assess the detection prospects of a gravitational wave background associated with sub-luminous gamma-ray bursts (SL-GRBs). We assume that the central engines of a significant proportion of these bursts are provided by newly born magnetars and consider two plausible GW emission mechanisms. First, the deformation-induced triaxial GW emission from a newly born magnetar. Secondly, the onset of a secular bar-mode instability, associated with the long-lived plateau observed in the X-ray afterglows of many gamma-ray bursts. With regards to detectability, we find that the onset of a secular instability is the most optimistic scenario: under the hypothesis that SL-GRBs associated with secularly unstable magnetars occur at a rate of (48–80) Gpc^(−3) yr^(−1) or greater, cross-correlation of data from two Einstein Telescopes (ETs) could detect the GW background associated to this signal with a signal-to-noise ratio of 3 or greater after 1 year of observation. Assuming neutron star spindown results purely from triaxial GW emissions, we find that rates of around (130–350) Gpc^(−3) yr^(−1) will be required by ET to detect the resulting GW background. We show that a background signal from secular instabilities could potentially mask a primordial GW background signal in the frequency range where ET is most sensitive. Finally, we show how accounting for cosmic metallicity evolution can increase the predicted signal-to-noise ratio for background signals associated with SL-GRBs.