Broken degeneracies: the rotation curve and velocity anisotropy of the Milky Way halo
نویسندگان
چکیده
منابع مشابه
The Tilt of the Halo Velocity Ellipsoid and the Shape of the Milky Way Halo
A sample of ∼1,800 halo subdwarf stars with radial velocities and proper motions is assembled from Bramich et al.’s (2007) light-motion catalog. This is based on the repeated multi-band Sloan Digital Sky Survey photometric measurements in Stripe 82. Our sample of halo subdwarfs is extracted via a reduced proper motion diagram and distances are obtained using photometric parallaxes, thus giving ...
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The last 10-20 years has seen a profound shift in views of how the Galaxy’s halo formed. The idea of a monolithic early collapse of a single system (Eggen, Lynden-Bell and Sandage 1962) has been challenged by observations at high redshift and by cosmological models of structure formation. These findings imply that we should see clear evidence of hierarchical formation processes in nearby galaxi...
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A simple model for the Milky Way halo is presented. It has a flat rotation curve in the inner regions, but the density falls off sharply beyond an outer edge. This truncated, flat rotation curve (TF) model possesses a rich family of simple distribution functions which vary in velocity anisotropy. The model is used to estimate the total mass of the Milky Way halo using the latest data on the mot...
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We measure the Galactic rotation curve and its first two vertical derivatives in the first and fourth quadrants of the Milky Way using the 21 cm VGPS and SGPS. We find tangent velocities of the atomic gas as a function of galactic longitude and latitude by fitting an analytic line profile to the edges of the velocity profiles. The shape of the analytic profile depends only on the tangent veloci...
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ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society: Letters
سال: 2012
ISSN: 1745-3925
DOI: 10.1111/j.1745-3933.2012.01283.x