New White Dwarfs In The Sloan Digital Sky Survey DR12

Some new white dwarfs are identified from the Sloan Digital Sky Survey(SDSS) Data Release 12(DR12). We develop the new color selection criteria for the searching of the white dwarfs from SDSS by the method based on artificial neural network. Based on our new color selection criteria, we find 2381 new white dwarfs, which includes 1899 DA white dwarfs, 40 DB white dwarfs, 22 DQ white dwarfs, 190 DZ white dwarfs, 10 magnetic white dwarfs and 133 White dwarfsM star binaries, from SDSS DR12. The SDSS observed spectra of hydrogen atmosphere(DA) and helium atmosphere(DB) white dwarfs are analyzed, and their effective temperature and surface gravity are estimated. The cooling times and masses of these white dwarfs are also derived based on the cooling models of the DA and DB WDs. We also analyze the spectra of the white dwarf-M star binaries and estimate their basic stellar parameters. Meanwhile, we find 26 high velocity WD candidates(with V?? 100 km s-1) based on their SDSS proper motions. It is important for investigating the dynamical evolution of the Milky Way.