New ultracool and halo white dwarf candidates in SDSS Stripe 82

作者：Vidrih S^*; Bramich D M; Hewett P C; Evans N W; Gilmore G; Hodgkin S; Smith M; Wyrzykowski L; Belokurov V; Fellhauer M; Irwin M J; McMahon R G; Zucker D; Munn J A; Lin H; Miknaitis G; Harris H C; Lupton R H; Schneider D P

来源：Monthly Notices of the Royal Astronomical Society, 2007, 382(2): 515-525.

DOI：10.1111/j.1365-2966.2007.12429.x

• catalogues
• stars : atmospheres
• stars : evolution
• white dwarfs

A 2 degrees.5 x 100 degrees region along the celestial equator (Stripe 82) has been imaged repeatedly from 1998 to 2005 by the Sloan Digital Sky Survey (SDSS). A new catalogue of similar to 4 million light-motion curves, together with over 200 derived statistical quantities, for objects in Stripe 82 brighter than r similar to 21.5 has been constructed by combining these data by Bramich et al. This catalogue is at present the deepest catalogue of its kind. Extracting similar to 130 000 objects with highest signal-to-noise ratio proper motions, we build a reduced proper motion diagram to illustrate the scientific promise of the catalogue. In this diagram, disc and halo subdwarfs are well-separated from the cool white dwarf sequence. Our sample of 1049 cool white dwarf candidates includes at least eight and possibly 21 new ultracool H-rich white dwarfs (T-eff < 4000 K) and one new ultracool He-rich white dwarf candidate identified from their SDSS optical and UKIDSS infrared photometry. At least 10 new halo white dwarfs are also identified from their kinematics.

• 出版日期2007-12-1