Measuring the Delay Time Distribution of Binary Neutron Stars. II. Using the Redshift Distribution from Third-generation Gravitational-wave Detectors Network
Measuring the Delay Time Distribution of Binary Neutron Stars. II. Using the Redshift Distribution from Third-generation Gravitational-wave Detectors Network
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DOI：
10.3847/2041-8213/ab22be
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发表时间：
2019-04
期刊：
影响因子：
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通讯作者：
M. Safarzadeh;E. Berger;K. Ng;Hsin-Yu Chen;S. Vitale;C. Whittle;E. Scannapieco
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文献类型：
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作者：
M. Safarzadeh;E. Berger;K. Ng;Hsin-Yu Chen;S. Vitale;C. Whittle;E. Scannapieco
我们研究了当前和第三代引力波 (GW) 探测器通过直接测量双中子星 (BNS) 合并率与红移函数的关系来确定双中子星 (BNS) 延迟时间分布 (DTD) 的能力。我们假设 DTD 遵循幂律分布，斜率为 Γ，最小合并时间为 tmin，并且还允许每单位恒星质量的总体 BNS 形成效率发生变化。通过将 DTD 和质量效率与宇宙恒星形成历史进行卷积，然后利用 GW 探测器功能，我们探索了两种相关的机制。首先，对于当前一代的引力波探测器来说，它们仅对本地宇宙敏感，但可以通过识别电磁对应物和宿主星系来实现精确的红移确定，我们表明，DTD参数在质量效率未知的情况下强烈简并，因此不能唯一确定。其次，对于爱因斯坦望远镜和宇宙探索者等第三代探测器，它们将在宇宙学距离上探测 BNS 合并，但具有仅 GW 探测固有的红移不确定性 (δ(z)/z ≈ 0.1z)，我们表明，经过一年的观测，DTD 和质量效率可以很好地限制在 10% 以上。这种通过直接映射 BNS 合并红移分布来确定 DTD 的长期方法将通过通过 BNS 合并宿主星系在 z ≈ 0 处的特性对 DTD 进行更近期的研究来补充。
We investigate the ability of current and third-generation gravitational wave (GW) detectors to determine the delay time distribution (DTD) of binary neutron stars (BNSs) through a direct measurement of the BNS merger rate as a function of redshift. We assume that the DTD follows a power-law distribution with a slope Γ and a minimum merger time tmin, and also allow the overall BNS formation efficiency per unit stellar mass to vary. By convolving the DTD and mass efficiency with the cosmic star formation history, and then with the GW detector capabilities, we explore two relevant regimes. First, for the current generation of GW detectors, which are only sensitive to the local universe but can lead to precise redshift determinations via the identification of electromagnetic counterparts and host galaxies, we show that the DTD parameters are strongly degenerate with the unknown mass efficiency and therefore cannot be determined uniquely. Second, for third-generation detectors such as Einstein Telescope and Cosmic Explorer, which will detect BNS mergers at cosmological distances but with a redshift uncertainty inherent to GW-only detections (δ(z)/z ≈ 0.1z), we show that the DTD and mass efficiency can be well constrained to better than 10% with a year of observations. This long-term approach to determining the DTD through a direct mapping of the BNS merger redshift distribution will be supplemented by more near-term studies of the DTD through the properties of BNS merger host galaxies at z ≈ 0.