论文标题
一项研究来自数值相对性模拟的二元中子星喷射模型之间的一致性
A study of the agreement between binary neutron star ejecta models derived from numerical relativity simulations
论文作者
论文摘要
中子恒星合并最近已成为研究极端重力，核合成和宇宙化学组成的工具。迄今为止，已经对二元中子星合并GW170817进行了一个联合引力和电磁观察，以及仅仅是重力观察GW190425。为了准确识别和解释中子星星合并的电磁信号，需要这些合并产生的更好的物质流出模型。我们比较了一系列的喷射模型，以查看它们在系统中预期的质量弹出质量量以及当前模型中的系统不确定性的位置提供了强大的限制，这使我们无法从观察到的事件中可靠地提取信息。我们还检查了与GW170817兼容的2396个状态恒星方程，以查看是否可以使用所述状态方程的中子星合理地生产给定的弹出质量，以及不同的喷射模型是否提供一致的预测。我们发现，模型之间的差异通常与这些模型通常假定的误差相当，这意味着需要在模型上有更好的约束。我们还注意到，在其校准窗口之外的流出模型的外推虽然通常需要分析引力波事件，但却是极其不可靠的，有时会导致完全毫无物理的结果。
Neutron star mergers have recently become a tool to study extreme gravity, nucleosynthesis, and the chemical composition of the Universe. To date, there has been one joint gravitational and electromagnetic observation of a binary neutron star merger, GW170817, as well as a solely gravitational observation, GW190425. In order to accurately identify and interpret electromagnetic signals of neutron star mergers, better models of the matter outflows generated by these mergers are required. We compare a series of ejecta models to see where they provide strong constraints on the amount of ejected mass expected from a system, and where systematic uncertainties in current models prevent us from reliably extracting information from observed events. We also examine 2396 neutron star equations of state compatible with GW170817 to see whether a given ejecta mass could be reasonably produced with a neutron star of said equation of state, and whether different ejecta models provide consistent predictions. We find that the difference between models is often comparable to or larger than the error generally assumed for these models, implying better constraints on the models are needed. We also note that the extrapolation of outflow models outside of their calibration window, while commonly needed to analyze gravitational wave events, is extremely unreliable and occasionally leads to completely unphysical results.
