论文标题
随机重力波背景和偏心恒星紧凑型二进制
Stochastic Gravitational Wave Background and Eccentric Stellar Compact Binaries
论文作者
论文摘要
来自众多宇宙恒星 - 紧凑型二进制的引力波（GW）辐射形成了随机GW背景（GWB），预计将来将通过地面和太空GW检测器检测到。该GWB的理论预测主要是通过假设圆形二进制文件和/或二元形成的特定通道获得的，这可能具有一些不确定性。在本文中，我们通过使用简单的模型来估计GWB及其频谱，以形成恒星质量二进制黑洞（SBBHS）和二元中子星（BNSS）。我们认为，与现场二进制恒星相比，动态起源的SBBH具有相对较大的质量和更高的偏心率及其对GWB光谱的影响。我们发现GWB频谱可能在低频（激光干涉仪空间天线； LISA）频段中具有失误，并且与单个具有独特索引$ 2/3 $的幂律相比，损坏的双重幂律可以更好地描述，而低频坡度则取决于动态的SBBBHS的重要性。我们进一步生成SBBHS和BNSS的模拟样本，并在时域中模拟模拟GWB菌株。我们发现，Lisa/Taiji/Tianqin的GWB可以通过信噪比（SNR）$ \ gtrsim274/255/21 $检测到超过$ 5 $ -Orears的观察，而Ligo $ 5 $ \ gtrsim3 $超过$ 2 $ - 年。此外，我们估计Lisa/Taiji/Tianqin可以单独检测到的SBBH数量，而SNR $ \ gtrsim8 $ IS $ \ sim5 $ - $ \ $ 221 $/$ 7 $ - $ 365 $/$ 3 $/$ 3 $ 3 $ - $ 3 $ 223 $ 223 $，超过$ 5 $ -Years的观察。
Gravitational wave (GW) radiations from numerous cosmic stellar-compact-binaries form a stochastic GW background (GWB), which is expected to be detected by ground and space GW detectors in future. Theoretical predictions of this GWB were mostly obtained by assuming either circular binaries and/or a specific channel for binary formation, which may have some uncertainties. In this paper, we estimate the GWB and its spectrum by using simple models for the formation of both stellar mass binary black holes (sBBHs) and binary neutron stars (BNSs). We consider that the dynamically originated sBBHs have relatively larger masses and higher eccentricities compared with those from field binary stars and its possible effect on the GWB spectrum. We find that the GWB spectrum may have a turnover in the low-frequency (Laser Interferometer Space Antenna; LISA) band and may be better described by a broken double power-law than a single power-law with the unique index $2/3$, and the low-frequency slope depends on the significance of the dynamically originated sBBHs with high eccentricities. We further generate mock samples of sBBHs and BNSs, and simulate the mock GWB strain in the time domain. We find that GWB can be detected with signal-to-noise ratio (SNR) $\gtrsim274/255/21$ by LISA/Taiji/TianQin over $5$-years' observation and $\gtrsim3$ by LIGO over $2$-years' observation. Furthermore, we estimate that the number of sBBHs that may be detected by LISA/Taiji/TianQin individually with SNR $\gtrsim8$ is $\sim5$-$221$/$7$-$365$/$3$-$223$ over $5$-years' observation.
