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

我利用斯巴鲁望远镜，超级最高凸轮（HSC）进行精确的自行测量，以探索那些微弱和高自行的物体，结合斯隆数字巡天（SDSS）。利用约化自行图将白色矮星从主序星中分离出来，建立了一个白色矮星目录。我们还采用黑体光谱拟合的方法对白色矮星的温度进行了验证和推导，特别是对白色矮星H/He模型难以拟合的低温矮星，我们发现了许多低于5,000 K的极低温白色矮星候选者。它们被认为是最古老的恒星群，是我们银河系的化石。我们可以通过测量白色矮星的性质来探测银河系早期的信息。另外，我们还可以完善红端的白色矮星冷却模型，在白色矮星目录的基础上，我们建立了白色矮星光度函数（WDLF），该函数可以恢复恒星的年龄和星星的形成历史，例如星星爆发在WDLF中会出现一个凸起。我们的WDLF显示了一种潜力，包括在以前的工作中从未发现过的内在微弱的白色矮星。

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.