研究実績の概要 |
I have completed the project on white dwarfs and their luminosity function. Utilizing the Hyper-Supreme Cam (HSC) of the Subaru Telescope, in conjunction with the Sloan Digital Sky Survey (SDSS), I conducted precise proper motion measurements to investigate faint white dwarfs, leading to the discovery of white dwarfs which has never been observed before. Furthermore, spectroscopic fitting was employed to validate and characterize the properties of these white dwarfs. Notably, a significant number of extremely low-temperature white dwarf candidates, with temperatures below 5,000K, were identified. These candidates are believed to represent the oldest stellar population, serving as fossils of our Milky Way Galaxy. Based on the white dwarf catalog, I constructed the white dwarf luminosity function (WDLF), extending its coverage to the very faint end for both the disk and halo regions. These faint white dwarfs are hypothesized to have originated from much older structures, such as Gaia-Enceladus, which have already merged into our Milky Way Galaxy.This study underscores the power of deep surveys like HSC, serving as a precursor to future surveys such as the Large Synoptic Survey Telescope (LSST).
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