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

基于Subaru HSC高速自行测量的致密天体研究

• 批准号: 22KJ0831
• 负责人: 邱 天
• 金额: $ 1.09万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for JSPS Fellows
• 财政年份: 2023
• 资助国家: 日本
• 起止时间: 2023-03-08 至 2024-03-31
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-22KJ0831/
• 关键词: White dwarf; Proper motion; Star forming history; Luminosity function

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.

我利用斯巴鲁望远镜，超级超级凸轮（HSC）进行精确的运动测量，以探索那些微弱和高运动的物体，并结合斯隆数字巡天（SDSS）。我已经建立了一个白矮星目录，通过应用简化的固有运动图来分离白矮星和主序星。采用黑体光谱拟合对白矮星的温度进行了验证和推导，特别是对难以用白矮星H/He模型拟合的低温白矮星进行了验证和推导。我发现了很多温度低于5000 k的极低温白矮星候选者。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矮星的性质来探测银河系早期的信息。此外，我们还可以完善红端白矮星的冷却模型。在白矮星星表的基础上，我制作了白矮星光度函数（WDLF），该函数已经被开发出来，用于恢复恒星的年龄和形成历史，例如恒星爆发将在WDLF中以凸起的形式出现。我们的WDLF显示出包含内在微弱白矮星的潜力，这在以前的工作中从未被发现过。