すばるHSCによる高速固有運動の測定に基づくコンパクト天体の研究

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I have taken advantage of the Subaru Telescope, Hyper-Supreme Cam (HSC) to make precise proper motion measurements to explore those faint and high proper motion objects, combining with the Sloan Digital Sky Survey (SDSS). I have established a white dwarf catalogue by applying the reduced proper motion diagram to separate the white dwarf from the main-sequence stars. A black-body spectroscopic fitting has also been adopted to make validation and derive the temperature of white dwarfs, especially the low-temperature ones which can hardly be fitted with white dwarfs H/He models.I have find a lot of extremely low-temperature white dwarf candidates lower than 5,000K. They are supposed to be the oldest population of stars, the fossil of our Milky Way Galaxy. We can measure the property of the white dwarfs to probe the information of the early time of the Galaxy. Besides, we can perfect the white dwarf cooling model at the red end.Based on the white dwarf catalogue, I have made the white dwarf luminosity function (WDLF), which has been developed to recover the age and star formation history, such as that star burst will appear as a bump in the WDLF. Our WDLF shows a potential to include the intrinsic faint white dwarfs which has never been discovered in previous work.