Discover of Brown Dwarfs with Virtual Observatories

We describe how to use cross-matching between the 2MASS and SDSS source catalogs to find brown dwarf candidates that are cooler and more distant than those discovered to date in the individual surveys. Our eventual goal is use the cross-matching to discover brown dwarf candidates from the large numbers of usually spurious single-band detections in each survey. A pilot study conducted for the NVO illustrates the power and promise of the method. This study searched for brown dwarf candidates that were detected only in the z-band in SDSS and in the J band in 2MASS. In our first trial we cross-matched all 2MASS Second Incremental Data Release (IDR2) sources falling within 3 arcseconds of an SDSS Early Data Release (EDR) source. The cross-match covered an area of roughly 150 square degrees and contains 326020 matches. Further filtering through a conservative z-J color cut recovered the known brown dwarfs in that area - a T dwarf (SDSS 1346-0031) and a late-L dwarf (SDSS 1326-0038) while also uncovering three more excellent brown dwarf candidates. One of these 2MASSI J0104075-005328) has been sprectroscopically identified as an L5 dwarf