@article {28016,
	title = {A Catalog of Spectroscopically Selected Close Binary Systems from the Sloan Digital Sky Survey Data Release Four},
	journal = {The Astronomical Journal},
	volume = {131},
	year = {2006},
	note = {n/a},
	month = {March 1, 2006},
	pages = {1674-1686},
	abstract = {We present a spectroscopic sample of 747 detached close binary systemsfrom the Sloan Digital Sky Survey (SDSS) Fourth Data Release. Themajority of these binaries consist of a white dwarf primary and alow-mass secondary (typically M dwarf) companion. We have determined thetemperature and gravity for 496 of the white dwarf primaries and thespectral type and magnetic activity properties for 661 of the low-masssecondaries. We have estimated the distances for each of the whitedwarf-main-sequence star binaries and use white dwarf evolutionary gridsto establish the age of each binary system from the white dwarf coolingtimes. With respect to a spectroscopically identified sample of ~8000isolated M dwarf stars in the SDSS, the M dwarf secondaries showenhanced activity with a higher active fraction at a given spectraltype. The white dwarf temperatures and gravities are similar to thedistribution of ~1900 DA white dwarfs from the SDSS. The ages of thebinaries in this study range from ~0.5 Myr to nearly 3 Gyr (average age~0.20 Gyr).
},
	url = {http://adsabs.harvard.edu/abs/2006AJ....131.1674S},
	author = {Silvestri, Nicole M. and Hawley, Suzanne L. and West, Andrew A. and Szkody, Paula and Bochanski, John J. and Eisenstein, Daniel J. and McGehee, Peregrine and Schmidt, Gary D. and Smith, J. Allyn and Wolfe, Michael A. and Harris, Hugh C. and Kleinman, Scot J. and Liebert, James and Nitta, Atsuko and Barentine, J. C. and Brewington, Howard J. and Brinkmann, John and Harvanek, Michael and Krzesi{\'n}ski, Jurek and Long, Dan and Neilsen, Eric H., Jr. and Schneider, Donald P. and Snedden, Stephanie A.}
}
