We have developed a method "photo-type" to identify and accurately classify L and T dwarfs, onto the standard system, from photometry alone. We combine SDSS, UKIDSS and WISE data and classify point sources by comparing the izYJHKW1W2 colours against template colours for quasars, stars, and brown dwarfs. In a sample of 6.5×106 bright point sources, J<17.5, from 3150 deg2, we identify and type 898 L and T dwarfs, making this the largest homogeneously selected sample of brown dwarfs to date. The sample includes 713 (125) new (previously known) L dwarfs and 21 (39) T dwarfs. For the previously-known sources, the scatter in the plot of photo-type vs spectral type indicates that our photo-types are accurate to 1.5 (1.0) sub-types rms for L (T) dwarfs. Peculiar objects and candidate unresolved binaries are identified.
@article{arxiv.1310.6613,
title = {Photometric brown-dwarf classification},
author = {N. Skrzypek and S. J. Warren},
journal= {arXiv preprint arXiv:1310.6613},
year = {2013}
}
Comments
3 pages, 2 figures, to appear in the proceedings of the conference "Brown Dwarfs Come of Age", 20-24th of May 2013, Fuerteventura, Canary Islands