Bibcode
Brown, W. R.; Geller, M. J.; Kenyon, S.; Kurtz, M.; Beers, T.; Allende Prieto, C.; Wilhelm, R.
Referencia bibliográfica
American Astronomical Society, 201st AAS Meeting, #105.03; Bulletin of the American Astronomical Society, Vol. 34, p.1273
Fecha de publicación:
12
2002
Número de citas
0
Número de citas referidas
0
Descripción
The Century Survey is a photometric survey strip from which we select
blue stars to probe the Milky Way halo. We obtain S/N=30 spectra for
every star with (V-R)<0.25 and V<16.5 mag in the 1o x
64o Century Survey strip, and for every star with
(J-H)<0.15 and J<15 mag in an adjacent 1o x
64o 2MASS region. The Century Survey is placed along a
roughly constant line of galactic longitude and spans 35o
< b < 88o. This placement allows us to measure
populations of stars and their systematic motions as a function of
galactic latitude. One of our primary goals is to use blue horizontal
branch stars to trace potential star streams in the halo and test the
hierarchal picture for the formation of the Galaxy. We present a sample
of 764 stars from the Century Survey. We measure radial velocities,
abundances, effective temperatures,surface gravities, and other physical
parameters from the spectra. Approximately half of the stars are F-types
located in the thick disk. The other half of the stars are A-types with
a +/- 105 km s-1 velocity dispersion consistent with a halo
population. We use three methods to distinguish blue horizontal branch
from higher surface gravity A-type stars, and identify 54 blue
horizontal branch stars to r=15 kpc in our sample. We look for
associations in velocity, abundance, and position. In addition, we find
a small number of unusual objects in the Century Survey, including white
dwarfs, quasars, and B-type stars at modest distances above the Galactic
plane.