The stellar content of the Hamburg/ESO survey. III. Field horizontal branch stars in the galaxy

Author(s)

Christlieb, N. ; Beers, Timothy C. ; Thom, C. ; Wilhelm, R. ; Rossi, Silvia ; Flynn, C. ; Wisotzki, L. ; Reimers, D.

• Document type: Journal article
• Source: Astronomy & Astrophysics; v. 431, n. 1, p. 143-148, Feb. 2005.
• Field of knowledge: Physical Sciences and Mathematics - Astronomy

Abstract

We present a sample of 8321 candidate Field Horizontal-Branch (FHB) stars selected by automatic spectral classification in the digital data base of the Hamburg/ESO objective-prism survey. The stars are distributed over 8225 square degrees of the southern sky, at [b] 30º. The average distance of the sample, assuming that they are all FHB stars, is 9.8 kpc, and distances of up to ~30 kpc are reached. Moderate-resolution spectroscopic follow-up observations and UBV photometry of 125 test sample stars demonstrate that the contamination of the full candidate sample with main-sequence A-type stars is < 16%, while it would be up to 50% in a flux-limited sample at high galactic latitudes. Hence more than ~6800 of our FHB candidates are expected to be genuine FHB stars. The candidates are being used as distance probes for high-velocity clouds and for studies of the structure and kinematics of the Galactic halo. (AU)

• FAPESP's process: 00/10406-4 - Chemical evolution and stellar populations of the galaxy, magellanic clouds and elliptical galaxies, based on spectroscopy and imaging
• Grantee: Beatriz Leonor Silveira Barbuy
• Support type: Research Projects - Thematic Grants