Late-time post-merger modeling of a compact binary: effects of relativity, r-process heating, and treatment of transport
Late-time post-merger modeling of a compact binary: effects of relativity, r-process heating, and treatment of transport
复制标题
DOI：
10.1088/1361-6382/acc0c6
复制
发表时间：
2022-08
影响因子：
3.5
通讯作者：
Milad Haddadi;Matthew D. Duez;F. Foucart;T. Ramirez;Rodrigo Fernández;Alexander L Knight;Jerred Jesse-Jerre
中科院分区：
文献类型：
--
作者：
Milad Haddadi;Matthew D. Duez;F. Foucart;T. Ramirez;Rodrigo Fernández;Alexander L Knight;Jerred Jesse-Jerre
致密双星合并产生的引力波的可探测电磁对应物可以通过合并后的前 10 秒内黑洞吸积盘残余物的流出而产生。具有有效粘度的二维轴对称模拟仍然是模拟这种合并后后期演变的有效且信息丰富的方法。除了轴对称的固有近似和通过粘度对湍流角动量传递进行建模之外，以前的模拟通常会进行与状态方程和湍流传递效应处理相关的其他简化。在本文中，我们测试了这些建模选择的效果。通过以相同的粘度发展先前在牛顿粘性流体动力学中发展的精确的合并后初始配置，我们发现牛顿处理提供了对圆盘喷射物质量的良好估计，但低估了流出速度。我们发现重核的包含导致喷射物质量显着增加。除了其对组合物的设计影响之外，近似包含 r 过程效应具有相对较小的影响。成分和熵的扩散，模拟湍流传输效应，具有减少喷射物质量并使其速度具有较低平均和更紧密峰值分布的总体效果。此外，我们还发现，即使在超过 10 000 公里的距离处，流出量也会显着加速，因此热风速只会渐近于超出此半径且值高于通常报道的值。
Detectable electromagnetic counterparts to gravitational waves from compact binary mergers can be produced by outflows from the black hole-accretion disk remnant during the first 10 s after the merger. Two-dimensional axisymmetric simulations with effective viscosity remain an efficient and informative way to model this late-time post-merger evolution. In addition to the inherent approximations of axisymmetry and modeling turbulent angular momentum transport by a viscosity, previous simulations often make other simplifications related to the treatment of the equation of state and turbulent transport effects. In this paper, we test the effect of these modeling choices. By evolving with the same viscosity the exact post-merger initial configuration previously evolved in Newtonian viscous hydrodynamics, we find that the Newtonian treatment provides a good estimate of the disk ejecta mass but underestimates the outflow velocity. We find that the inclusion of heavy nuclei causes a notable increase in ejecta mass. An approximate inclusion of r-process effects has a comparatively smaller effect, except for its designed effect on the composition. Diffusion of composition and entropy, modeling turbulent transport effects, has the overall effect of reducing ejecta mass and giving it a speed with lower average and more tightly-peaked distribution. Also, we find significant acceleration of outflow even at distances beyond 10 000 km, so that thermal wind velocities only asymptote beyond this radius and at higher values than often reported.