The KPD survey for galactic plane ultraviolet-excess objects Space densities of white dwarfs and subdwarfs

Abstract

view Abstract Citations (125) References (62) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The KPD Survey for Galactic Plane Ultraviolet-Excess Objects: Space Densities of White Dwarfs and Subdwarfs Downes, R. A. Abstract A survey for ultraviolet-excess objects has been performed for over about 1000 sq deg of the Galactic plane. Photographic blue and ultraviolet plates were obtained to select ultraviolet-excess candidates, and spectroscopic observations were used to determine the nature of those objects. Over 70 white dwarfs and subdwarfs were identified from the survey plates, and these objects were analyzed statistically to determine scale heights and space densities. The sample was complete to B = 15.3 mag, with the space density of white dwarfs for Mv of less than 12.25 equal to 0.72 + or 0.25/1000 cu pc, slightly higher than that from the Palomar-Green survey. The average absolute magnitude determined for both the subdwarf O and the subdwarf B stars was considerably fainter than previous determinations, while the scale height for the subdwarfs was lower than earlier suggested values. The space density for the subdwarf O stars is about 7 x 10 to the -7th/cu pc, while the value for the subdwarf B stars is about 2 x 10 to the -6th/cu pc, both values considerably higher than previous estimates. The space densities can be used to place evolutionary constraints on these objects. Publication: The Astrophysical Journal Supplement Series Pub Date: July 1986 DOI: 10.1086/191124 Bibcode: 1986ApJS...61..569D Keywords: Blue Stars; Subdwarf Stars; Ultraviolet Astronomy; White Dwarf Stars; Interstellar Extinction; Photographic Plates; Stellar Magnitude; Astrophysics; STARS: FAINT BLUE; STARS: STELLAR STATISTICS; STARS: SUBDWARFS; STARS: WHITE DWARFS full text sources ADS | data products SIMBAD (94) CDS (2) Related Materials (1) Catalog: 2009yCat..20610569D