Effects of Rotation on Stochasticity of Gravitational Waves in the Nonlinear Phase of Core-collapse Supernovae
Effects of Rotation on Stochasticity of Gravitational Waves in the Nonlinear Phase of Core-collapse Supernovae
复制标题
核心塌陷超新星非线性阶段自转对引力波随机性的影响
DOI：
10.1088/0004-637x/736/2/124
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
Naofumi
中科院分区：
文献类型：
--
作者：
Kotake;Kei ; Iwakami-Nakano;Wakana ; Ohnishi;Naofumi
通过执行三维（3D）模拟，证明了中微子驱动的核心坍缩超新星在常压吸积激波不稳定性（SASI）的帮助下，我们研究了SASI的螺旋模式如何影响引力波（GW）发射的特性。为了观察旋转在非线性反弹后阶段的影响，我们给出了从铁核外边界平流的均匀旋转，其特定角动量假定与最近的恒星演化模型一致。我们计算了15个三维模型，其中初始角动量和来自质子中子星的输入中微子光度以系统的方式改变。通过射线追踪分析，我们准确地估计了各向异性中微子发射产生的GW振幅。我们的结果表明，在包含旋转的模型中，中微子的引力波表现出一个共同的特征；否则，在没有旋转的情况下，它们的变化更加随机。随机性的破坏源于平行于自旋轴的过量中微子发射。这是因为由于螺旋SASI模式的增长，物质在赤道面附近的压缩得到了更大的增强，从而形成了在较高温度下围绕自旋轴循环的螺旋流。我们指出，最近提出的未来空间干涉仪，如fabry - perot型DECIGO，将允许探测到银河系超新星的这些信号。
By performing three-dimensional (3D) simulations that demonstrate the neutrino-driven core-collapse supernovae aided by the standing accretion shock instability (SASI), we study how the spiral modes of the SASI can impact the properties of the gravitational-wave (GW) emission. To see the effects of rotation in the nonlinear postbounce phase, we give a uniform rotation on the flow advecting from the outer boundary of the iron core, the specific angular momentum of which is assumed to agree with recent stellar evolution models. We compute fifteen 3D models in which the initial angular momentum and the input neutrino luminosities from the protoneutron star are changed in a systematic manner. By performing a ray-tracing analysis, we accurately estimate the GW amplitudes generated by anisotropic neutrino emission. Our results show that the gravitational waveforms from neutrinos in models that include rotation exhibit a common feature; otherwise, they vary much more stochastically in the absence of rotation. The breaking of the stochasticity stems from the excess of the neutrino emission parallel to the spin axis. This is because the compression of matter is more enhanced in the vicinity of the equatorial plane due to the growth of the spiral SASI modes, leading to the formation of the spiral flows circulating around the spin axis with higher temperatures. We point out that recently proposed future space interferometers like Fabry–Perot-type DECIGO would permit the detection of these signals for a Galactic supernova.