Electromagnetic transients from radioactive decays accompanying short gamma-ray bursts

最后的螺旋阶段和随后的两个中子星或一个中子星星和一个恒星质量黑洞的合并是在千赫制度的主要引力波源。此外，它们被认为是（短）伽马射线暴现象背后的“中心引擎”。在合并过程中，重力力矩将减压的中子星星物质发射到未束缚或几乎未束缚的偏心轨道。这些碎片由放射性原子核组成，最终衰变为所谓的r过程（“快速中子俘获”）元素，这种衰变必然会产生各向同性、明亮但快速衰减的电磁瞬变。识别这种瞬变是至关重要的，因为它增加了地面引力波探测器设施的有效灵敏度，并通过提供关于宿主星系、当地环境和双星星星性质和演变的信息，将紧凑的双星合并置于天体物理学背景下。因此，当前和未来的瞬态测量可以限制宇宙中最重元素的未知来源。这一建议的目的是克服后一种限制，并对碎片材料的演变（包括核能释放对流体力学的反馈）的最初合并过程到最后的光变曲线进行完整的计算。

The final inspiral stages and the subsequent coalescence of two neutron stars or of a neutron star and a stellar-mass black hole are the prime gravitational wave sources in the kilohertz regime. Moreover, they are thought to be the "central engines" behind the (short) Gamma-ray burst phenomenon. During the merging process, gravitational torques launch decompressed neutron star matter into unbound or nearly unbound, eccentric orbits. This debris consists of radioactive nuclei that finally decay into so-called r-process ("rapid neutron capture") elements and this decay must produce an isotropic, bright, but rapidly decaying electromagnetic transient. The identification of such transients is crucial since it increases the effective sensitivity of ground-based gravitational wave detector facilities and it places compact binary mergers in an astrophysical context by providing information on the host galaxy, the local environment and on binary star properties and evolution. Thus, current and future transient surveys can constrain the still unknown origin of the heaviest elements in the Universe. The aim of this proposal is to overcome the latter restriction and to perform a complete calculation from the initial merger process over the evolution of the debris material (including feedback from nuclear energy release onto the hydrodynamics) to the final light curves.