Ultracool Astrophysics from Substellar Binaries

在这个项目中，刘博士和他的研究小组将对已知最冷的褐矮星进行深入、灵敏的搜索，以确定适合动态质量测定的新的亚恒星双星，并寻找比目前已知的任何东西都更冷的自由漂浮物体。他们将尝试通过一个主要的观测项目，利用凯克激光导星自适应光学系统的近衍射极限红外成像和光谱学，来发现更多这些天体的例子，并将扩大对次恒星双星的动态质量测量样本。虽然在研究褐矮星的总体特性方面已经取得了很大的进展，但对低质量、超冷天体的理论预测在很大程度上还未经检验，尽管这些模型被广泛用于描述已知的次恒星和系外行星种群。本建议的研究目标将与培训初级同事的更广泛影响一起完成。下一代天文学家将接受快速发展的次恒星天体物理学和自适应光学科学领域的培训。特别是，激光导星自适应光学系统的观测技术和专业知识的发展是迈向未来高角分辨率地面天文学的重要一步。

In this project, Dr. Liu and his research group will conduct a deep, sensitive search of the coldest known brown dwarfs to identify new substellar binaries suitable for dynamical mass determinations and to search for free-floating objects colder than anything currently known. They will attempt to uncover more examples of these objects through a major observational program employing near-diffraction limited infrared imaging and spectroscopy from the Keck laser guide star adaptive optics system, and will expand the sample of dynamical mass measurements for substellar binaries. While there has been great progress in studying the bulk properties of brown dwarfs, theoretical predictions of low-mass, ultracool objects are largely untested even though such models are widely used to characterize the known substellar and exoplanetary population.The research goals of this proposal will be accomplished in tandem with the broader impact of training junior colleagues. This next generation of astronomers will receive training in the rapidly growing fields of substellar astrophysics and science with adaptive optics. In particular, development of observational techniques and expertise with laser guide star adaptive optics systems is an important step toward future high angular resolution ground-based astronomy.