Multiband gravitational wave observations of stellar binary black holes at the low to middle and high frequencies

Abstract

The ground-based gravitational wave (GW) observatories discover a population of merging stellar binary black holes (BBHs), which are promising targets for multiband observations by the low-, middle-, and high-frequency GW detectors. In this paper, we investigate the multiband GW detections of BBHs and demonstrate the advantages of such observations in improving the localization and parameter estimates of the sources. We generate mock samples of BBHs by considering different formation models as well as the merger rate density constrained by the current observations (GWTC-3). We specifically consider the astrodynamical middle-frequency interferometer GW observatory (AMIGO) in the middle-frequency band and estimate that it may detect 21-91 BBHs with signal-to-noise ratio ϱ ≥ 8 in a 4-year observation period. The multiband observations by the low-frequency detectors [Laser Interferometer Space Antenna (LISA) and Taiji] and AMIGO may detect 5-33 BBHs with ϱLT ≥ 5 and ϱAMI ≥ 5, which can evolve to the high-frequency band within 4 years and can be detected by the Cosmic Explorer (CE) and Einstein Telescope (ET). The joint observations of LISA-Taiji-AMIGO-ET-CE may localize the majority of the detectable BBHs in sky areas of 7 × 10−7-2 × 10−3 deg2, which is improved by a factor of ∼120, ∼2.4 × 105, ∼1.8 × 104, or ∼1.2 × 104, comparing with those by only adopting CE-ET, AMIGO, LISA-Taiji, or LISA-Taiji-AMIGO. These joint observations can also lead to an improvement of the measurement precision of the chirp mass (symmetric mass ratio) by a factor of ∼5.5 × 104 (33), ∼16 (8), ∼120 (90), or ∼5 (5), comparing with those by CE-ET, AMIGO, LISA-Taiji, or LISA-Taiji-AMIGO.

Space gravitational wave detection: Progress and outlook

“…多波段黑洞双星系统参数估计不确定性分布的中位数值 [107] 。 Table 1. Median values of the distributions of parameter estimation uncertainties for multiband BBHs [107] . Notes.…”

“…The third column, the fourth column, and the last column show the corresponding results for the distributions of relative uncertainty of luminocity distance σdL/dL, the relative uncertainty of red-shifted chirp mass σMc/Mc, and the uncertainty of relative symmetric mass ratio ση, respectively. For the low and high values of the 68 percent confidence interval of each of these values, see reference [107].…”

“…在这个的仿真研究中 [107]，为了研究从旋进阶 段演化到最终并合阶段的双黑洞系统引力波多频带 观测的前景，考虑了不同的形成途径及 LVK O3 的 观测约束 [108] 之四种不同的模型: 前三种模型的本地 并合速率密度 R(0)归一化到 LVK 在前三次观测运行 之后提供的最新约束值 [108]…”

“…AMIGO ≥8, magenta lines), respectively. All the BBHs plotted here are assumed to be observed for a continuous period of 4 yr. Orange, pink, sky blue, green, and purple curves represent the sensitivity curves for LISA, Taiji, AMIGO, CE, and ET, respectively [107]. , 后者以 Folkner 低频空间任务概念为例 [114] , 并建议以 类 gLISA [115][116][117][118] 方案为第三种可能.…”

“…. 这些波源属于正常 Ia 型超新星和特殊超新星 前身的群体。 有关致密天体引力波并合的电磁对应体 的综述，请参见参考文献 [311] 。在 3-6 mHz 频段， LISA/Taiji 比 微 赫 兹 低 频 引 力 波 探 测 任 务 概 念 ASTROD-GW、Folkner's 任务、LISAmax 更敏感(图 12)。LISA/Taiji 将先发射，除了作为验证双星之外， 这些信号还可用作低频引力波探测任务的校准双星 [312,313,314] 。 在引力波频率低于几毫赫兹时，约一千万个致密 双星将形成 LISA/Taiji 和微赫兹低频引力波探测器 的可探测前景 [315][316][317][318][319][320][321][322] 。 在这些频率下，微赫兹低频引 力波探测器比豪赫兹低频引力波探测器更敏感(图 12)。更多引力波源将被分别探测到，微赫兹低频引 力波探测器将可以改进豪 赫 兹 低 频 引 力 波 探 测 器 LISA 和 Taiji/TianQin 的观测结果 [322] 。 地基引力波探测器已探测到双中子星并合和超百 组恒星级质量黑洞并合。从已有的观测推论出的分布 密度，期待豪赫兹低频引力波探测器将探测到数十到 数百个含中子星、恒星级质量黑洞、或白矮星并合事 件。 这些事件将会使我们进一步了解各类并合过程 [51] 。 节 1.9、表 1 和图 10 在讨论豪赫兹低频引力波、 中频引力波和高频引力波多波段观测仿真中，说明了 对恒星级质量黑洞并合的观测，对宇宙模型参数和哈 勃常数的测定精度可以达到甚至超越千分之一，将大 步推动对宇宙和暗能量的了解 [107] [49] (LISA/Taiji/TianQin 和 ASTROD-GW/Folkner's 空间任务/LISAmax)和脉冲星定时阵列 [179,[323][324][325] 4 -10 7 M。LISA/Taiji 预期可检测的引力波事件可 达千次至数千次 [51] ；ASTROD-GW 类似或更多，对较大 的中心黑洞更具有较高的灵敏度，并且具有更好的角 分辨率(第 10.3 节)。 9.4. 测试相对论引力 豪赫兹低频引力波探测的一个重要科学目标是检 验广义相对论并在强引力下精确研究黑洞物理 [45,51] 。 [328,329] 。凭借更好 的角分辨率(第 10.3 节)，微赫兹低频引力波探测 将有更好的机会识别相关的电磁红移，因此将更好地 确定暗能量状态方程 [80,81] .…”