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1999MNRAS.310..645W - Mon. Not. R. Astron. Soc., 310, 645-662 (1999/December-2)
The present and future mass of the Milky Way halo.
WILKINSON M.I. and EVANS N.W.
Abstract (from CDS):
A detailed analysis of the uncertainties in our estimate is presented, including the effects of the small data set, possible incompleteness or correlations in the satellite galaxy sample and the measurement errors. The most serious uncertainties come from the size of the data set, which may cause a systematic underestimate by a factor of 2, and the measurement errors, which cause a scatter in the mass of the order of a factor of 2. We conclude that the total mass of the halo is ∼1.9–1.7+3.6x1012M☉, while the mass within 50kpc is ∼5.4–3.6+0.2x1011M☉. In the near future, ground-based radial velocity surveys of samples of blue horizontal branch (BHB) stars are a valuable way to augment the sparse data set. A data set of ∼200 radial velocities of BHB stars will reduce the uncertainty in the mass estimate to ∼20per cent. In the coming decade, microarcsecond astrometry will be possible with the Space Interferometry Mission (SIM) and the Global Astrometry Interferometer for Astrophysics (GAIA) satellites. For example, GAIA can provide the proper motions of the distant dwarfs like Leo I to within ±15km.s–1 and the nearer dwarfs like Ursa Minor to within ±1km.s–1. This will also allow the total mass of the Milky Way to be found to ∼20per cent. SIM and GAIA will also provide an accurate estimate of the velocity normalization of the halo potential at large radii.
Abstract Copyright: 1999, Royal Astronomical Society
Journal keyword(s): Galaxy: fundamental parameters - Galaxy: halo - Galaxy: kinematics and dynamics
Simbad objects: 28
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