No Peaks without Valleys: The Stable Mass Transfer Channel for Gravitational-wave Sources in Light of the Neutron Star–Black Hole Mass Gap
No Peaks without Valleys: The Stable Mass Transfer Channel for Gravitational-wave Sources in Light of the Neutron Star–Black Hole Mass Gap
复制标题
DOI：
10.3847/1538-4357/ac9b0a
复制
发表时间：
2022-09
期刊：
影响因子：
--
通讯作者：
L. V. van Son;S. D. de Mink;M. Renzo;S. Justham;E. Zapartas;K. Breivik;T. Callister;W. Farr
中科院分区：
文献类型：
--
作者：
L. V. van Son;S. D. de Mink;M. Renzo;S. Justham;E. Zapartas;K. Breivik;T. Callister;W. Farr
引力波探测开始揭示双致密物体的质量分布特征。黑洞（BH）质量分布的低端特别有趣，因为这里几乎没有形成通道，而且因为它比高质量端更能抵抗宇宙星星形成的变化。在这项工作中，我们探讨了稳定的质量传递通道的GW源的形成，重点是低质量端的质量分布。我们对影响这一通道的不确定物理过程进行了广泛的探索。我们注意到，对于基准假设，这个通道非常好地再现了GW观测到的双星BH质量分布中的109 M的峰值，并预测了与假定的中子星-黑洞（NS-BH）质量间隙的上边缘相一致的截止质量。峰值和截止质量是该通道的独特性质的结果;即（1）质量传递阶段期间的稳定性要求，以及（2）最终紧凑物体质量与初始质量成比例的复杂方式。我们提供了一个分析表达式的主要组成部分质量的截止，并表明，这充分匹配我们的数值结果。我们的研究结果表明，选择效应产生的形成通道单独可以提供一个解释的传说NS-BH质量间隙GW检测。这为通常采用的观点提供了一种替代方案，即在BH形成期间出现差距。
Gravitational-wave (GW) detections are starting to reveal features in the mass distribution of double compact objects. The lower end of the black hole (BH) mass distribution is especially interesting as few formation channels contribute here and because it is more robust against variations in the cosmic star formation than the high-mass end. In this work we explore the stable mass transfer channel for the formation of GW sources with a focus on the low-mass end of the mass distribution. We conduct an extensive exploration of the uncertain physical processes that impact this channel. We note that, for fiducial assumptions, this channel reproduces the peak at ∼9 M ☉ in the GW-observed binary BH mass distribution remarkably well and predicts a cutoff mass that coincides with the upper edge of the purported neutron star–black hole (NS–BH) mass gap. The peak and cutoff mass are a consequence of the unique properties of this channel; namely (1) the requirement of stability during the mass transfer phases, and (2) the complex way in which the final compact object masses scale with the initial mass. We provide an analytical expression for the cutoff in the primary component mass and show that this adequately matches our numerical results. Our results imply that selection effects resulting from the formation channel alone can provide an explanation for the purported NS–BH mass gap in GW detections. This provides an alternative to the commonly adopted view that the gap emerges during BH formation.