Distant field BHB stars and the mass of the Galaxy II: Photometry and spectroscopy of UKST candidates 16<B<19.5, 11<R<52 kpc

Simple item page
dc.creatorClewley, L.
dc.creatorWarren, S. J.
dc.creatorHewett, P. C.
dc.creatorNorris, John E.
dc.creatorEvans, N. W.
dc.date2004-04-16
dc.date.accessioned2026-07-07T10:27:12Z
dc.date.available2026-07-07T10:27:12Z
dc.descriptionThis is the second in a series of papers presenting a new calculation of the mass of the Galaxy based on radial velocities and distances for a sample of faint 16 < B < 21.3 field blue horizontal-branch (BHB) stars. We present accurate BV CCD photometry and spectra for 142 candidate A-type stars selected from ub_jr photometry of UK Schmidt telescope plates in six high-Galactic-latitude fields. Classification of these candidates produces a sample of 60 BHB stars at distances of 11-52 kpc from the Sun (mean 28 kpc), with heliocentric line-of-sight velocities accurate to 15 km/s, and distance errors < 10%. We provide a summary table listing coordinates and velocities of these stars. The measured dispersion of the radial component of the Galactocentric velocity for this sample is 108+-10 km/s, in agreement with a recent study of the distant halo by Sirko and coworkers. Measurements of the Ca II K line indicate that nearly all the stars are metal-poor with a mean [Fe/H] = -1.8 with dispersion 0.5. Subsequent papers will describe a second survey of BHBs to heliocentric distances 70 < R < 125 kpc and present a new estimate of the mass of the Galaxy.
dc.description16 pages, 15 figures. Accepted for publication in MNRAS
dc.identifierhttps://arxiv.org/abs/astro-ph/0404322
dc.identifierhttp://arxiv.org/abs/astro-ph/0404322
dc.identifierMon.Not.Roy.Astron.Soc.352:285,2004
dc.identifierdoi:10.1111/j.1365-2966.2004.07921.x
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/177083
dc.subjectAstrophysics
dc.titleDistant field BHB stars and the mass of the Galaxy II: Photometry and spectroscopy of UKST candidates 16<B<19.5, 11<R<52 kpc
dc.typetext

Files

Collections

arXiv