论文标题
具有弱相互作用的中子星级合并的GRMHD模拟：动态喷射的R过程核合成和电磁特征
GRMHD simulations of neutron-star mergers with weak interactions: r-process nucleosynthesis and electromagnetic signatures of dynamical ejecta
论文作者
论文摘要
在二进制中子明星（BNS）系统合并期间，动态弹出的快速材料会导致系统的引力波发射，从而导致独特的电磁对应物，可以用作“吸烟枪”，以区分BNS和NS-Black-Hole-Hole-Hole-Hole合并。我们基于与BNS合并的三维一般性相关的磁性磁动力学模拟相关的Kilonova前体和Kilonova余辉的新型Ab-Initio建模，其与列表的，依赖于组成的，有限的状态方程（EOSS）（EOSS），弱相互作用，弱相互作用和近似中性转运。我们分析了从1.35-1.35msun二进制组中的动态质量喷射，这是银河系双NS系统的典型特征，并与第一个观察到的BNS合并GW170817的性质一致，使用三个核EOSS跨越了允许的紧凑型。核反应网络计算产生强大的第二至第三峰R-Process。我们发现很少有1e-6msun的快速（$ v> 0.6 $ c）弹射器，它们会在〜YR时限上产生宽带同步加速器的发射，这与最近的GW170817后过量X射线/无线电排放的近期初步证据一致。我们发现2e-5msun的自由中子子在<h时间尺度上为基洛诺瓦前体提供动力。由于先前被忽视的相对论效应（合并后的10小时），紫外线/光学亮度提高了一些因素，可提供有希望的前景，可通过紫外线/光学望远镜（例如Swift或Ultrasat）（例如，诸如Swift或Ultrasat）以未来的检测到250mpc。我们发现，由于高度电离的灯笼在〜70000K处高度电离引起的不透明度提升不太可能基于获得的弹出结构影响kilonova Lightcurve的早期。在此处发现的软性EOSS动态射出组合物中的方位角不均匀性（“兰烷基/actinide口袋”）可能会对基尔洛诺瓦早期和延迟时间的烟囱发射产生可观察的后果。
Fast material ejected dynamically over $<10$ ms during the merger of a binary neutron-star (BNS) system can give rise to distinctive electromagnetic counterparts to the system's gravitational-wave emission that can serve as a "smoking gun" to distinguish between a BNS and a NS-black-hole merger. We present novel ab-initio modeling of the associated kilonova precursor and kilonova afterglow based on three-dimensional general-relativistic magneto-hydrodynamic simulations of BNS mergers with tabulated, composition-dependent, finite-temperature equations of state (EOSs), weak interactions, and approximate neutrino transport. We analyze dynamical mass ejection from 1.35-1.35Msun binaries, typical of Galactic double-NS systems and consistent with properties of the first observed BNS merger GW170817, using three nuclear EOSs that span the range of allowed compactness. Nuclear reaction network calculations yield a robust 2nd-to-3rd-peak r-process. We find few 1e-6Msun of fast ($v>0.6$c) ejecta that give rise to broad-band synchrotron emission on ~yr timescales, consistent with recent tentative evidence for excess X-ray/radio emission following GW170817. We find 2e-5Msun of free neutrons that power a kilonova precursor on <h timescale. A boost in early UV/optical brightness by a factor of a few due to previously neglected relativistic effects, with appreciable enhancements up to 10h post-merger, provides promising prospects for future detection with UV/optical telescopes such as Swift or ULTRASAT out to 250Mpc. We find that a recently predicted opacity boost due to highly ionized lanthanides at ~70000K is unlikely to affect the early kilonova lightcurve based on the obtained ejecta structures. Azimuthal inhomogeneities in dynamical ejecta composition for soft EOSs found here ("lanthanide/actinide pockets") may have observable consequences for both early kilonova and late-time nebular emission.
