Compact Object Forensics: The Question of Origin

西北大学的Vassiliki Kalogera博士将进行一项全面的研究项目，以解决与中子星和黑洞起源有关的基本问题。这项研究将利用最近观测限制的增长提供的一个独特的机会，对包含吸积中子星或黑洞的银河系和河外X射线双星的大量样本进行研究。她将从事理论计算，其中包括模拟X射线双星进化史所需的许多元素：银河系中的运动、质量传递及其对轨道偏心率的依赖、由于核燃烧而分离的双星系统的演化、恒星潮汐和角动量损失，以及核心塌缩事件对双星轨道动力学的影响。她还将从事已知系统和双星群体的统计分析，以确定最有可能的前身属性和X射线双星形成通道。结果将包括对致密物体的直接祖先的物理约束，以及关于其受约束属性的可能性的统计陈述。这些将被用作堆芯坍塌流体动力学模拟的初始条件，这将检验和加深我们对堆芯坍塌过程的理解。这项工作将有助于回答目前尚未解决的关于致密天体形成的基本问题。例如，致密天体和它们的祖先之间的质量关系是什么？是不是有些中子星的初生期比我们想象的要低得多？核心塌缩过程中的不对称性和电子俘获超新星的作用意味着什么？大多数黑洞是否需要相当大的初生阶段，它们的形成与中子星的形成有何不同？经过观测选择偏差校正后，黑洞质量的真实分布是什么？卡洛杰拉博士将通过公开演讲、在少数族裔会议和机构发表演讲、参加芝加哥地区及其他地区的学校科学博览会等方式，继续她的推广工作。她正在与西北大学和芝加哥阿德勒天文馆和天文博物馆的可视化和图形专家合作，开发适合普通公众的可视化片段，讲述致密物体如何在相互作用的双星中形成和演化的故事。这些产品将在西北大学阿德勒天文馆展出，并将通过网站广泛传播。

Dr. Vassiliki Kalogera of Northwestern University will undertake a comprehensive research project to address fundamental questions concerning the origin of neutron stars and black holes. The research will take advantage of a unique opportunity provided by recent growth in observational constraints for a sizable sample of Galactic and extragalactic X-ray binaries harboring accreting neutron stars or black holes. She will engage in theoretical computations which incorporate many elements necessary for the modeling of X-ray binary evolutionary histories: motion in the Galaxy, mass transfer and its dependence on orbital eccentricity, evolution of detached binary systems due to nuclear burning, stellar tides and angular momentum losses,and the effect of the core-collapse event on binary orbital dynamics. She will also engage in statistical analyses of known systems and binary populations to determine most likely progenitor properties and X-ray binary formation channels. The results will include physical constraints on the immediate progenitors of compact objects and statistical statements about the likelihood of their constrained properties. These will be used as initial conditions for core-collapse hydrodynamic simulations which will test and further our understanding of the core-collapse process. The work will contribute to answering currently open, basic questions about compact object formation. What, for example, is the mass relationship between compact objects and their progenitors? Do some neutron stars acquire natal kicks with magnitudes considerably lower than was thought before? What are the implications for asymmetries in the core-collapse process and the role of electron-capture supernovae? Do most black holes require sizable natal kicks and how is their formation different from that of neutron stars, if at all? What is the true distribution of black hole masses, corrected for observational selection biases?Dr. Kalogera will continue her outreach efforts through public lectures, talks at minority conferences and institutions, participation in school science fairs in the Chicago area and beyond. She is working in collaboration with visualization and graphics experts at Northwestern and the Adler Planetarium and Astronomy Museum in Chicago to develop visualization segments appropriate for the general public telling the story of how compact objects form and evolve in interacting binaries. The products will be presented at Northwestern, the Adler Planetarium, and will be available through web sites for broad dissemination.