THE ANISOTROPIC SPATIAL DISTRIBUTION OF HYPERVELOCITY STARS

Warren R. Brown(1), Margaret J. Geller(1), Scott J. Kenyon(1) Benjamin C. Bromley(2)


(1) Smithsonian Astrophysical Observatory, 60 Garden St, Cambridge, MA 02138
(2) Department of Physics, University of Utah, 115 S 1400 E, Rm 201, Salt Lake City, UT 84112

Paper: ApJ, 2009, 690, L69


Abstract:

We study the distribution of angular positions and angular separations of unbound hypervelocity stars (HVSs). HVSs are spatially anisotropic at the 3- sigma level. The spatial anisotropy is significant in Galactic longitude, not in latitude, and the inclusion of lower velocity, possibly bound HVSs reduces the significance of the anisotropy. These observations are plausibly explained by an anisotropic central bulge potential. In the future, measuring the distribution of HVSs in the southern sky will provide additional constraints on the spatial anisotropy and the origin of HVSs.


Preprints available from the authors at wbrown@cfa.harvard.edu , or the raw TeX (no figures) if you click here.

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