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.
