Exploring the dynamics and dark halos of elliptical galaxies at large radii

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Title:	Exploring the dynamics and dark halos of elliptical galaxies at large radii
Author:	Forestell, Amy Dove
Abstract:	Dark matter is now accepted as an integral part of our universe, and galaxy dynamics have long provided the most convincing observational evidence for dark matter. Spiral galaxies have traditionally been used for these studies because of their more simple kinematics, however elliptical galaxies need to be understood as well. In this dissertation I present deep long-slit spectroscopy from the University of Texas’ Hobby-Eberly Telescope for a sample of elliptical galaxies. For a subsample of galaxies I fit axisymmetric orbit-superposition models with a range of dark halo density profiles. I find that all three galaxies modeled require a significant dark halo to explain their motions. However, the shape of the dark halo is not the expected NFW profile, but rather a profile with a flat central slope. I also discuss the galaxy masses, anisotropies, and stellar mass-to-light ratios.
Department:	Astronomy
Subject:	Dark matter Elliptical galaxies Deep long-slit spectroscopy Dark halos Hobby-Eberly telescope Axisymmetric orbit-superposition models Galaxy masses Anisotropies Stellar mass-to-light ratios
URI:	http://hdl.handle.net/2152/6641
Date:	2009-08