An independent test of the photometric selection of white dwarf candidates using LAMOST DR3

In previous work by Gentile Fusillo et al., we developed a selection method for white dwarf candidates which makes use of photometry, colours and proper motions to calculate a probability of being a white dwarf (PWD). The application of our method to the Sloan Digital Sky Survey (SDSS) data release 10 resulted in similar or equal to 66 000 photometrically selected objects with a derived PWD, approximately similar or equal to 21 000 of which are high-confidence white dwarf candidates. Here, we present an independent test of our selection method based on a sample of spectroscopically confirmed white dwarfs from the Large Sky Area Multi-Fiber Spectroscopic Telescope (LAMOST) survey. We do this by cross-matching all our similar or equal to 66 000 SDSS photometric white dwarf candidates with the over 4 million spectra available in the third data release of LAMOST. This results in 1673 white dwarf candidates with no previous SDSS spectroscopy, but with available LAMOST spectra. Among these objects, we identify 309 genuine white dwarfs. We find that our PWD can efficiently discriminate between confirmed LAMOST white dwarfs and contaminants. Our white dwarf candidate selection method can be applied to any multiband photometric survey and in this work we conclusively confirm its reliability in selecting white dwarfs without recourse to spectroscopy. We also discuss the spectroscopic completeness of white dwarfs in LAMOST, as well as deriving effective temperatures, surface gravities and masses for the hydrogen-rich atmosphere white dwarfs in the newly identified LAMOST sample.Science and Technology Facilities Council (STFC); Postdoctoral Science Foundation of China [2013M530470, 2014T70010]; Research Fund for International Young Scientists by the National Natural Science Foundation of China [11350110496]; European Research Council under the European Union [320964]; National Development and Reform Commission; Alfred P. Sloan Foundation; National Science Foundation; U.S. Department of Energy Office of Science; National Aeronautics and Space Administration [NNG05GF22G]; U.S. National Science Foundation [AST-0909182, AST-1313422]SCI(E)ARTICLEn.p.gentile-fusillo@warwick.ac.uk1765-77345