The motion of stars near the Galactic center: A comparison of the black hole and fermion ball scenarios

Faustin Munyaneza and Raoul D. Viollier


(1) Institute of Theoretical Physics and Astrophysics, Department of Physics, University of Cape Town, Private Bag, Rondebosch 7701, South Africa, fmunyaneza@hotmail.com, viollier@physci.uct.ac.za

Paper: ApJ, submitted

EPrint Server: astro-ph/0103466


Abstract:

After a discussion of the properties of degenerate fermion balls, we analyze the orbits of the stars S0-1 and S0-2, which have the smallest projected distances to Sgr A*, in the supermassive black hole as well as in the fermion ball scenarios of the Galactic center. It is shown that both scenarios are consistent with the data, as measured during the last six years by Genzel et al. and Ghez et al. The free parameters of the projected orbit of a star are the unknown components of its velocity v_z and distance z to Sgr A* in 1995.4, with the z-axis being in the line of sight. We show, in the case of S0-1 and S0-2, that the z-v_z phase- space, which fits the data, is much larger for the fermion ball than for the black hole scenario. Future measurements of the positions or radial velocities of S0-1 and S0-2 could reduce this allowed phase-space and eventually rule out one of the currently acceptable scenarios. This may shed some light into the nature of the supermassive compact dark object, or dark matter in general at the center of our Galaxy.


Preprints available from the authors at bilic@physci.uct.ac.za , or the raw TeX (no figures) if you click here.

Back to the gcnews home-page.