论文标题
关于GW190814的形成
On the formation of GW190814
论文作者
论文摘要
Ligo-Virgo合作最近报道了一个令人困惑的事件GW190814，零件质量为23和2.6太阳能。以这种结合的相对较小的速度和次级的质量接近已知的二元中子星（BNS）系统的总质量，我们提出GW190814是从层次三级系统中的第二代合并，即从BNS Coalge Remge com nieral coalge com and Merge Black（BH）（BH）（BH）。我们表明，只要在BNS结合时，外轨道的半轴轴小于几个AU，就会发生这种情况。是否通常在宇宙中实现这种紧密三重系统的形成的条件，尤其是在低金属性（小于0.1太阳能）环境中，还有待探索。我们的模型提供了许多预测。 （1）GW190814样系统中次级的自旋为0.6至0.7。 （2）来自大型LIGO来源样本的组分质量分布应具有2.5至〜3.5 msun的狭窄峰值，而〜3.5至〜5 MSUN之间的范围为空（前提是恒星进化不会在“质量差距”中产生此类BHS）。 （3）在10 MHz的重力波频率附近，大约90％（10％）类似于GW190814的事件的偏心率为E> 2x10^{ - 3}（> 0.1）。 （4）BNS合并的显着比例应在重力波形中以几个AU的距离具有大型第三纪的签名。 （5）有10^5个未被发现的无线电BNS系统，具有大量的BH第三纪。
The LIGO-Virgo collaboration recently reported a puzzling event, GW190814, with component masses of 23 and 2.6 solar masses. Motivated by the relatively small rate of such a coalescence and the fact that the mass of the secondary is close to the total mass of known binary neutron star (bNS) systems, we propose that GW190814 was a second-generation merger from a hierarchical triple system, i.e., the remnant from the bNS coalescence was able to merge again with the 23 Msun black hole (BH) tertiary. We show that this occurs at a sufficiently high probability provided that the semimajor axis of the outer orbit is less than a few AU at the time of bNS coalescence. It remains to be explored whether the conditions for the formation of such tight triple systems are commonly realized in the Universe, especially in low metallicity (less than 0.1 solar) environments. Our model provides a number of predictions. (1) The spin of the secondary in GW190814-like systems is 0.6 to 0.7. (2) The component mass distribution from a large sample of LIGO sources should have a narrow peak between 2.5 and ~3.5 Msun, whereas the range between ~3.5 and ~5 Msun stays empty (provided that stellar evolution does not generate such BHs in the "mass gap"). (3) About 90% (10%) of GW190814-like events have an eccentricity of e > 2x10^{-3} (> 0.1) near gravitational wave frequency of 10 mHz. (4) A significant fraction (> 10%) of bNS mergers should have signatures of a massive tertiary at a distance of a few AU in the gravitational waveform. (5) There are 10^5 undetected radio-quiet bNS systems with a massive BH tertiary in the Milky Way.
