论文标题
Protonutron Star Asterosemology中相对论凌管近似的准确性
Accuracy of relativistic Cowling approximation in protoneutron star asteroseismology
论文作者
论文摘要
在流体振荡期间忽略了度量扰动的相对论整流量近似，通常用于考虑通过核心偏离超新星爆炸提供的原始恒星（PNSS）的引力波。在这项研究中，我们通过将频率与套管近似与没有近似值的频率进行比较来评估整流罩近似如何效果很好。然后，我们发现，具有近似值的频率的行为与没有近似值的方式在质量上相同，在$ \ sim 20 \％$ $准确度中，具有近似值的频率可以完全确定。特别是，具有整流罩近似值的基本模式被高估了。此外，我们还讨论了来自PNSS的引力波中各种本本征谱的阻尼时间，在$ F $和$ G_1 $ -MODES之间避免穿过PNSS的阻尼时间与冷中子星的交叉相似，但与以后的中子星星相似或更小。与经常在分析中经常使用的短期变换的典型时间间隔相比，阻尼时间足够长，并且理想地保证了转换的有效性。
The relativistic Cowling approximation, where the metric perturbations are neglected during the fluid oscillations, is often adopted for considering the gravitational waves from the protoneutron stars (PNSs) provided via core-collapse supernova explosions. In this study, we evaluate how the Cowling approximation works well by comparing the frequencies with the Cowling approximation to those without the approximation. Then, we find that the behavior of the frequencies with the approximation is qualitatively the same way as that without the approximation, where the frequencies with the approximation can totally be determined within $\sim 20\%$ accuracy. In particular, the fundamental mode with the Cowling approximation is overestimated. In addition, we also discuss the damping time of various eigenmodes in gravitational waves from the PNSs, where the damping time for the PNSs before the avoided crossing between the $f$- and $g_1$-modes, is quite different from that for cold neutron stars, but it is more or less similar to that for cold neutron stars in the later phase. The damping time is long enough compared to the typical time interval of short-Fourier transformation that often used in the analysis, and that ideally guarantees the validity of the transformation.
