A catalog of spectroscopically selected close binary systems from the sloan digital sky survey data release four

作者：Silvestri NM^*; Hawley SL; West AA; Szkody P; Bochanski JJ; Eisenstein DJ; McGehee P; Schmidt GD; Smith JA; Wolfe MA; Harris HC; Kleinman SJ; Liebert J; Nitta A; Barentine JC; Brewington HJ; Brinkmann J; Harvanek M; Krzesinski J; Long D; Neilsen EH; Schneider DP; Snedden SA

来源：Astronomical Journal, 2006, 131(3): 1674-1686.

DOI：10.1086/499494

• binaries : close
• novae, cataclysmic variables
• stars : activity
• stars : low-mass
• brown dwarfs
• white dwarfs

We present a spectroscopic sample of 747 detached close binary systems from the Sloan Digital Sky Survey ( SDSS) Fourth Data Release. The majority of these binaries consist of a white dwarf primary and a low- mass secondary ( typically M dwarf) companion. We have determined the temperature and gravity for 496 of the white dwarf primaries and the spectral type and magnetic activity properties for 661 of the low- mass secondaries. We have estimated the distances for each of the white dwarf - main- sequence star binaries and use white dwarf evolutionary grids to establish the age of each binary system from the white dwarf cooling times. With respect to a spectroscopically identified sample of similar to 8000 isolated M dwarf stars in the SDSS, the M dwarf secondaries show enhanced activity with a higher active fraction at a given spectral type. The white dwarf temperatures and gravities are similar to the distribution of similar to 1900 DA white dwarfs from the SDSS. The ages of the binaries in this study range from similar to 0.5Myr to nearly 3 Gyr ( average age similar to 0.20 Gyr).

• 出版日期2006-3