Fully general relativistic simulation of merging binary clusters: Spatial gauge condition
Fully general relativistic simulation of merging binary clusters: Spatial gauge condition
复制标题
合并双星团的完全广义相对论模拟：空间规范条件
DOI：
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发表时间：
1999
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影响因子：
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通讯作者：
M. Shibata
中科院分区：
文献类型：
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作者：
M. Shibata
我们已经进行了模拟的两个相对论集群之间的碰撞粒子的合并使用三维数值相对论代码。我们采用了一个新的空间规范条件，它是通过对Smarr和约克提出的最小畸变规范条件稍加修改而得到的，从而得到了一个更简单的位移矢量方程。使用这种规范条件，我们已经进行了几次模拟的合并两个相同的集群之间，我们有不同的压缩，在集群中的内部运动的类型，和轨道速度的大小。合并的结果是形成一个新的旋转星系团或一个黑洞。在黑洞没有形成的情况下，模拟可以进行比动力学时间尺度长得多的时间，并且由此产生的引力波形被相当准确地计算出来：在这些情况下，发出的引力波的振幅可以是$sim 10^{-18}（M/10^6M_{odot}）$，并合最后阶段的引力波辐射可能耗散了静止质量能量的0.5%。这些结果证实，新的空间规范条件是有前途的许多问题，至少到黑洞的形成。另一方面，在黑洞形成的情况下，规范条件似乎不太合适，但我们建议在这种情况下改进它。所有的结果证实了我们制定的鲁棒性和我们的代码的能力，稳定发展的强引力场的紧凑的双星。
We have carried out simulations of the coalescence between two relativistic clusters of collisionless particles using a 3D numerical relativity code. We have adopted a new spatial gauge condition obtained by slightly modifying the minimum distortion gauge condition proposed by Smarr and York and resulting in a simpler equation for the shift vector. Using this gauge condition, we have performed several simulations of the merger between two identical clusters in which we have varied the compaction, the type of internal motion in the clusters, and the magnitude of the orbital velocity. As a result of the coalescence, either a new rotating cluster or a black hole is formed. In the case in which a black hole is not formed, simulations could be carried out for a time much longer than the dynamical time scale, and the resulting gravitational waveforms were calculated fairly accurately: In these cases, the amplitude of gravitational waves emitted can be $sim 10^{-18}(M/10^6M_{odot})$ at a distance 4000Mpc, and $sim 0.5%$ of the rest mass energy may be dissipated by the gravitational wave emission in the final phase of the merger. These results confirm that the new spatial gauge condition is promising in many problems at least up to the formation of black holes. In the case in which a black hole is formed, on the other hand, the gauge condition seems to be less adequate, but we suggest a strategy to improve it in this case. All of the results obtained confirm the robustness of our formulation and the ability of our code for stable evolution of strong gravitational fields of compact binaries.