David Merritt


Also archived in: arXiv: astro-ph/9601091 v1 17 Jan 1996 AND Rutgers Astrophysics Preprint Series No. 186 Hubble Space Telescope (HST) observations reveal that the density of stars in most elliptical galaxies rises toward the center in a power-law cusp. Many of these galaxies also contain central dark objects, possibly supermassive black holes. The gravitational force from a steep cusp or black hole will destroy most of the box orbits that constitute the “backbone” of a triaxial stellar system. Detailed modelling demonstrates that the resulting chaos can preclude a self-consistent, strongly triaxial equilibrium. Most elliptical galaxies may therefore be nearly axisymmetric, either oblate or prolate.

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M. Valluri carried out the calculations on which Fig. 3 was based, and made helpful comments on the manuscript. S. Tremaine, as referee, also made a number of suggestions that improved the presentation. This work was supported by NSF grant AST 93-18617 and by NASA grant NAG 5-2803. ISSN: 1095-9203

Document Type


Department, Program, or Center

School of Physics and Astronomy (COS)


RIT – Main Campus