标题： 三维旋转引力坍缩的引力波发射 显示英文标题

标题： Gravitational-Wave Emission from Rotating Gravitational Collapse in three Dimensions

摘要： 我们首次计算了均匀旋转的中子星坍缩成黑洞时产生的引力波辐射，并进行了完全三维模拟。 初始的恒星模型是相对论多态体，它们动力学上不稳定，且角速度范围从慢速旋转到质量剥离极限。 这些模拟的一个关键方面是使用了逐步网格细化技术，这使得可以将计算域的外边界移动到引力辐射达到渐近形式的区域。 波形提取采用了规范不变的方法，其中数值时空与史瓦西时空的非球面扰动相匹配。 总体而言，结果表明波形具有与初始恒星模型性质（以w模式振荡的形式）和新生成的旋转黑洞（以准正规模式）相关的特征。 尽管我们的波形在定性上与Stark和Piran在二维模拟中计算的结果一致，但我们的振幅大约小一个数量级，这种差异很可能是因为我们的压力降低程度较轻。 对于接近质量剥离且在10千秒差距处坍缩的中子星，仅从爆发计算得到的信噪比约为S/N ~ 0.25，但在LIGO II的情况下，该值增长至S/N <~ 4。 显示英文摘要

摘要： We present the first calculation of gravitational wave emission produced in the gravitational collapse of uniformly rotating neutron stars to black holes in fully three-dimensional simulations. The initial stellar models are relativistic polytropes which are dynamically unstable and with angular velocities ranging from slow rotation to the mass-shedding limit. An essential aspect of these simulations is the use of progressive mesh-refinement techniques which allow to move the outer boundaries of the computational domain to regions where gravitational radiation attains its asymptotic form. The waveforms have been extracted using a gauge-invariant approach in which the numerical spacetime is matched with the non-spherical perturbations of a Schwarzschild spacetime. Overall, the results indicate that the waveforms have features related to the properties of the initial stellar models (in terms of their w-mode oscillations) and of the newly produced rotating black holes (in terms of their quasi-normal modes). While our waveforms are in good qualitative agreement with those computed by Stark and Piran in two-dimensional simulations, our amplitudes are about one order of magnitude smaller and this difference is mostly likely due to our less severe pressure reduction. For a neutron star rotating uniformly near mass-shedding and collapsing at 10 kpc, the signal-to-noise ratio computed uniquely from the burst is S/N ~ 0.25, but this grows to be S/N <~ 4 in the case of LIGO II.