Collaborative Research: White Dwarfs in Binaries Across the H-R Diagram with the APOGEE-GALEX-Gaia Catalog

超过95%的恒星最终会变成白矮星，白矮星是耗尽核燃料、坍缩到与地球大小相当、质量与太阳相当的恒星的残骸。许多这样的白矮星被锁在与恒星伴星的宇宙之舞中，在那里它们围绕彼此运行并交换质量。如此紧密的白矮星双星系统为研究恒星演化的后期阶段提供了绝佳的机会。它们还可以用作银河系动力学的示踪剂，它们是引力波的潜在来源。这个项目的目标是在广泛的波长范围内收集这些系统的数据，以表征它们并研究它们的基本特性，比如它们是由什么组成的，它们共有多少质量。这项工作还将为不同阶段的理科生提供几个项目，研究人员将与无障碍领域的专家合作，制定培训计划，向盲人和视障人士教授天文学。大多数白矮星居住在多个系统中，其中很大一部分足够紧凑，可以交换质量，改变两颗恒星的结构和随后的演化。调解这些质量交换的物理机制包括共同包络演化、罗氏叶溢出、风吸积、质量剥离和恒星合并。本提案的主要目标是通过组装数千个传质后双星的独特观测样本，进一步了解相互作用系统中的传质过程。源样本将GALEX和Gaia数据库与APOGEE数据库结合起来——高分辨率（R= 22500）、高信噪比、多历元、红外（1.51 μm至1.69 μm），对整个银河系的恒星进行光谱调查——建立最详尽的后质量传递双星调查，包括主序星、亚巨星、红巨星和红团伴星。APOGEE-GALEX-Gaia星表的创建以及对结果数据集的分析将提高我们对包含白矮星的后质量转移双星的总体认识，并绘制出它们的属性变化作为非简并伴星演化的函数。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

More than 95 percent of stars will eventually end up as white dwarfs - the remains of stars that have used up their nuclear fuel and collapsed to a size equivalent to Earth but with a mass comparable to the Sun. Many of these white dwarfs are locked in a cosmic dance with stellar companions, where they orbit around each other and exchange mass. Such close white dwarf binary systems offer an excellent opportunity to study the late stages of stellar evolution. They can also be used as tracers of the dynamics of the Milky Way galaxy, and they are potential sources of gravitational waves. The goal of this project is to collect data on these systems at a wide range of wavelengths to characterize them and investigate fundamental properties, like what they are made of and how much mass they are sharing. This work will also provide several projects for science students at various stages, and the investigators will work with experts in accessibility to create training programs to teach astronomy to blind and visually impaired people. Most white dwarfs inhabit multiple systems, and a large fraction of those are compact enough to exchange mass, changing the structures and subsequent evolution of both stars. The physical mechanisms that mediate these mass exchanges include common envelope evolution, Roche lobe overflow, wind accretion, mass stripping, and stellar mergers. The main goal of this proposal is to further our understanding of mass transfer processes in interacting systems by assembling a unique observational sample of thousands of post mass-transfer binaries. The source sample combines the GALEX and Gaia databases with APOGEE — a high resolution (R=22,500), high signal-to-noise, multi-epoch, infrared (1.51 μm to 1.69 μm), spectroscopic survey of stars across the Milky Way — to build the most exhaustive survey of post-mass transfer binaries, containing systems with main sequence, subgiant, red giant, and red clump companions. The creation of this APOGEE-GALEX-Gaia Catalog and the proposed analysis of the resulting data set will improve our knowledge of the population of post-mass transfer binaries containing a white dwarf, and map the changes in their properties as a function of the evolution of the non-degenerate companion.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.