Increasing the accuracy of binary neutron star simulations with an improved vacuum treatment
Increasing the accuracy of binary neutron star simulations with an improved vacuum treatment
复制标题
DOI：
10.1103/physrevd.102.104014
复制
发表时间：
2020-09
影响因子：
5
通讯作者：
Amit Poudel;W. Tichy;B. Brügmann;T. Dietrich
中科院分区：
文献类型：
--
作者：
Amit Poudel;W. Tichy;B. Brügmann;T. Dietrich
相对论数值模拟是研究中子星星合并最后阶段的必要手段。不幸的是，为了稳定的模拟，需要添加人工低密度大气。在这里，我们讨论了一个新的框架，在这个框架中，我们可以有效地将中子星周围的密度设置为零，以确保更准确的模拟。我们测试我们的方法与一些单星星测试案例和一个等质量的二进制中子星星模拟。虽然系统的整体运动不受影响，因此，没有改善相对于发射的引力波信号，我们发现，新的方法是上级相对于质量守恒，它允许更好地跟踪向外移动的材料。这将允许更准确地模拟喷出的物质，并支持用更准确的数值相对论模拟来解释现在和未来的多信使观测。
Numerical relativity simulations are essential to study the last stages of the binary neutron star coalescence. Unfortunately, for stable simulations there is the need to add an artificial low-density atmosphere. Here we discuss a new framework in which we can effectively set the density surrounding the neutron stars to zero to ensure a more accurate simulation. We test our method with a number of single star test cases and for an equal mass binary neutron star simulation. While the bulk motion of the system is not influenced, and hence, there is no improvement with respect to the emitted gravitational-wave signal, we find that the new approach is superior with respect to mass conservation and it allows a much better tracking of outward moving material. This will allow a more accurate simulation of the ejected material and supports the interpretation of present and future multi-messenger observations with more accurate numerical relativity simulations.