AI 中文总结
本文提出一种基于模式恢复力能量的自动分类方案，对核心坍缩超新星中原中子星的振荡模式分类，识别出不同模式族，为引力波信号的参数估计奠定基础。
AI 中文摘要
新生原中子星（PNS）是引力波星震学的潜在研究目标，该学科通过恒星的振荡模式研究恒星内部结构。为了为当前及未来引力波天文台最终探测这类模式做好准备，理论研究已获得振荡的可能频谱，但在根据激发它们的物理机制对特定模式进行识别和分类时存在分歧。本文提出了一种新方案，用于对核心坍缩超新星（CCSNe）中被停滞吸积激波包围的新生PNS的振荡模式进行分类。该分类具有物理依据，基于模式恢复力的能量，通过考虑模式起源的CCSNe不同区域来研究模式的本质。我们将该方案应用于一组28个非旋转的1D、2D和3D CCSNe模拟，这些模拟采用两种不同的数值代码，使用不同的前身星和物态方程。由此发现系统中存在不同的f-、p-和g-模式族，分布在不同区域；更具体地说，我们识别出分别与PNS和激波相关的两个f-和p-模式族，以及源自两个对流稳定区域的两个g-模式族，一个位于PNS核心，另一个靠近其表面。我们还发现，主导的高频发射模式是PNS的f-模式，与PNS表面的强密度梯度相关。我们的分类过程是自动的，对所有考虑的模型表现一致，为系统研究模式频率对PNS属性的依赖铺平了道路，可直接应用于未来引力波信号观测的参数估计。
英文摘要
Newborn proto-neutron stars (PNS) are potential targets of gravitational wave asteroseismology, the study of the (inner) structure of stars via their oscillation modes. To prepare for the eventual detection of such modes by current and future gravitational wave observatories, theoretical studies have obtained the possible spectrum of oscillations. However, there has been disagreement when it comes to identifying and classifying specific modes according to the physical mechanism that excites them. In this paper, we present a novel scheme to classify the oscillation modes of a newly born PNS surrounded by a stalled accretion shock in core-collapse supernovae (CCSNe). Our classification is physically motivated, as it is based on the energy of the restoring forces of the mode. We investigate the nature of the modes by considering the different regions of the CCSN that they stem from. We apply this scheme to a set of 28 non-rotating 1D, 2D and 3D CCSN simulations performed with two different numerical codes and using different progenitors and equations of state. In that way, we find that there are different families of f-, p- and g-modes in the system, living in different areas. More specifically, we identify two families of f- and p-modes associated with the PNS and the shock, respectively, and two families of g-modes originating from the two convectively stable regions, one in the PNS core and one near its surface. We also find that the dominant high-frequency emission mode is the f-mode of the PNS, associated with the strong density gradient at its surface. Our classification procedure is automatic, performs consistently for all the models considered, and paves the way to systematic studies of the dependence of the mode frequencies on the PNS properties, with direct application to parameter estimation from future observations of gravitational wave signals.
Comments30 pages, 15 figures, submitted to PRD
