A Snapshot A-Star Survey for Substellar Companions

With high resolution adaptive optics images from the NIRC2 camera on the Keck II telescope, we have performed a companion search around approximately 200 young B and A stars within 150 pc. The goal of this survey is to identify possible brown dwarf companions for follow up confirmation and characterization. Through this survey, which will expand the number of candidate companion brown dwarfs, future work will allow for benchmark comparisons to formation models of planets and brown dwarfs, more accurate population/frequency statistics, and follow-up spectroscopy for atmospheric characterization of planetary temperature objects observable with high signal-to-noise ratio. We utilize a custom data reduction pipeline which includes PSF subtraction through Reference Differential Imaging performed using the pyKLIP software to identify faint candidate companions. This pipeline combined with the adaptive optics system on the telescope allows us to achieve the high contrast necessary for detecting wide separation brown dwarf companions around bright host stars. We present the candidate brown dwarfs and their estimated masses and separations, along with the achieved contrast for this survey.