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arXiv 2410.04522astro-ph.COastro-ph.GA
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银河系(亚)太阳质量原初黑洞引力波背景的探测前景

Detection prospects for the GW background of Galactic (sub)solar mass primordial black holes

Frans van Die, Ivan Rapoport, Yonadav Barry Ginat, Vincent Desjacques

AI总结:

本文研究了银河系中(亚)太阳质量原初黑洞双星产生的引力波背景及其探测前景,发现其信号在毫赫兹频段达到峰值,并给出了LISA及未来DECIGO、BBO等探测器的可探测条件与预期事件数。

摘要:

在多组分暗物质模型中,暗物质的一部分 $f_\text{pbh}$ 可能以(亚)太阳质量的原初黑洞(PBHs)形式存在。其中一些会形成双星系统,目前正追踪着银河系中粒子暗物质的晕。我们研究了这种假设的银河系PBH双星群所产生的引力波(GW)信号,并评估了LISA实验对其的可探测性。为此,我们对早期型PBH双星的形成和演化进行了建模,考虑了银河系中的引力波硬化和双星瓦解过程。我们的分析表明,现今银河系中的PBH双星群具有非常高的轨道偏心率 $|1-e|\ll 1$。对于PBH质量 $M_{\rm pbh} \sim 0.1 - 1 M_\odot$,这会产生一个在毫赫兹频段达到峰值的引力波背景,而该频段正是LISA仪器噪声最小的区域。尽管对于可行的 $f_\text{pbh}\lesssim 0.01$ 而言,该信号仍低于LISA的探测阈值,但未来的引力波观测站如DECIGO和BBO在 $0.01\lesssim M_{\rm pbh} \lesssim 0.1 M_\odot$ 的条件下可以探测到它。此外,我们预计,经过5年的观测,如果 $f_{\rm pbh}=0.01$(对应地 $f_{\rm pbh}=0.001$),LISA应能以信噪比 $\geq 5$ 探测到 $\mathcal{O}(100)$(对应地 $\mathcal{O}(1)$)个响亮的、质量为 $M_{\rm pbh} \sim 0.1 - 1 M_\odot$ 的银河系PBH双星。本文未考虑的非线性效应,如质量吸积和动力学俘获,可能会改变这些预测。

英文摘要:

In multi-component dark matter models, a fraction $f_\text{pbh}$ of the dark matter could be in the form of primordial black holes (PBHs) with (sub)solar masses. Some would have formed binaries that presently trace the Milky Way halo of particle dark matter. We explore the gravitational wave (GW) signal produced by such a hypothetical population of Galactic PBH binaries and assess its detectability by the LISA experiment. For this purpose, we model the formation and evolution of early-type PBH binaries accounting for GW hardening and binary disruption in the Milky Way. Our analysis reveals that the present-day Galactic population of PBH binaries is characterized by very high orbital eccentricities $|1-e|\ll 1$. For a PBH mass $M_{\rm pbh} \sim 0.1 - 1 M_\odot$, this yields a GW background that peaks in the millihertz frequency range where the LISA instrumental noise is minimum. While this signal remains below the LISA detection threshold for viable $f_\text{pbh}\lesssim 0.01$, future GW observatories such as DECIGO and BBO could detect it if $0.01\lesssim M_{\rm pbh} \lesssim 0.1 M_\odot$. Furthermore, we anticipate that, after 5 years of observations, LISA should be able to detect $\mathcal{O}(100)$ (resp. $\mathcal{O}(1)$) loud Galactic PBH binaries of mass $M_{\rm pbh} \sim 0.1 - 1 M_\odot$ with a SNR $\geq 5$ if $f_{\rm pbh}=0.01$ (resp. $f_{\rm pbh}=0.001$). Nonlinear effects not considered here such as mass accretion and dynamical capture could alter these predictions.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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