Evolution of Compact Binaries and Related Objects

一些最有趣的天体物理现象与包含简并和/或致密天体的双星和多星星系统有关。它们涵盖了从高能射线爆发到宇宙中观测到的最明亮的爆炸的范围。 这些系统中的许多系统的性质只能在恒星在先前的演化过程中通过交换质量相互作用的情况下得到解释。随着引力波天文学（2030年代的LIGO和丽莎）的出现，对双星系统，特别是超紧双星系统中恒星演化的研究变得更加紧迫。 拟议的研究的主要目标是作出重大贡献，创造一个统一的图片的形成，演化和各种类型的紧凑双星和相关系统的最终状态。这包括对激变变星（CV）、接触双星、类藻双星、低质量X射线双星、毫秒脉冲星和Ia型超新星之间相互关系的更好理解。这些目标将通过使用复杂的恒星演化代码（例如梅萨）来实现，以确定CV是否可以从更大质量的祖星演化而来。 通过分析在这些系统中观察到的化学丰度，我们相信我们将能够回答这个问题。 我们还将寻找可能产生一个或多个简并恒星（包括EL CVn型双星）的更不寻常的演化路径。 确定Ia型超新星的祖先是特别困难的，因为天文学家将它们视为“可测量的蜡烛”，因此依靠它们来确定宇宙尺度上的距离和其他参数。 我们将通过使用两个流体动力学代码来重新讨论Ia型SN祖先问题，以确定哪些类型的伴星是可以接受的。 我们还将研究能量不足事件（Iax型）的内在相关问题，以确定推定伴随事件发生了多少消融。 我们工作的另一个主要目标是发现和分析与上述目标（以及系外行星）密切相关的目标，作为正在进行或即将进行的大规模调查的后续行动。这包括对来自开普勒，K2，特别是TESS，以及SDSS，Pan-STARRS，LSST和JWST的数据产品的分析。 与这些发现相关的辅助科学是开创性的。我们的团队已经做好充分准备，充分利用即将到来的大量新数据。

Some of the most astrophysically interesting phenomena are associated with binary and multiple star systems containing degenerate and/or compact objects. They span the gamut from high energy -ray bursts to the most luminous explosions observed in the Universe. The properties of many of these systems can only be explained if the stars interacted by exchanging mass during their prior evolution. With the advent of gravitational wave astronomy (LIGO and LISA in the 2030s), the study of the evolution of stars in binaries, especially ultracompact binaries, has taken on a new urgency. The primary objective of the proposed research is to make significant contributions to the creation of a unified picture for the formation, evolution, and final states of various types of compact binaries and related systems. This includes an improved understanding of the inter-relationships between Cataclysmic Variables (CVs), Contact Binaries, Algol-like Binaries, Low-Mass X-ray Binaries, Millisecond Pulsars, and Type Ia Supernovae. These objectives will be carried out by using sophisticated stellar evolution codes such as MESA to determine if, for instance, CVs could have evolved from much more massive progenitor stars. By analyzing the chemical abundances observed in these systems we believe that we will be able to answer this question. We will also look for more unusual evolutionary paths that might produce one or more degenerate stars (including EL CVn-type binaries). The determination of the progenitors of Type Ia SNe is particularly problematic since astronomers treat them as “standardizable candles” and thus rely on them to determine distances and other parameters on a cosmic scale. We will revisit the Type Ia SN progenitor problem by using two hydrodynamic codes to determine which types of companion stars are admissible. We will also look at the intrinsically related problem of under-energetic events (Type Iax) to determine how much ablation of the putative companions occurs. Another major objective of our work is to discover and analyze targets that are closely related to the ones described above (as well as exoplanets) as a follow-up to large-scale surveys that are either ongoing or are imminent. This includes the analysis of data products from Kepler, K2, and especially TESS, but also from SDSS, Pan-STARRS, LSST, and the JWST. The ancillary science associated with these discoveries is ground-breaking. Our group is well poised to take advantage of the multitude of new data that will be forthcoming.