AAS 205th Meeting, 9-13 January 2005
Session 93 Dwarf Galaxies
Poster, Wednesday, January 12, 2005, 9:20am-6:30pm, Exhibit Hall

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[93.05] Ages, Metallicities & Kinematics in Fornax dEs

B. Rojas (UChile), B. Miller (Gemini), J. Lotz (UCSC), M. Hilker (UBonn)

Dwarf elliptical galaxies (dEs) are the most common type of galaxy in the universe but there is as yet no consensus on their physical structure or how they form. Therefore, we have obtained medium resolution (R=5200) spectra with the NTT at La Silla in order to determine radial velocities, velocity dispersions, ages, and metallicities of 6 dE,Ns in the Fornax Cluster. Preliminary results are presented here. Radial velocities were computed via Fourier cross correlation with velocity standards. Two galaxies show strong rotation and their (v/\sigma)\ast values suggest that they are flattened by rotation. The velocity dispersions are essentially flat with radius. The H\beta and MgFe (González 1993) absorption line indices have been used to determine the ages and metallicities, respectively, of the nuclei. Four of the six appear to be old (~3-15 Gyr) but two, the two dS0s with rotational support, have ages between 3 and 4 Gyr. The metallicities vary between nearly solar and the metallicities of metal-poor Galactic globulars. We will also discuss the mass-to-light ratios, the locations of the galaxies in the fundamental plane, and the ages and metallicities of the underlying galaxies. These results will help us to distinguish between various theories of dE galaxy formation.

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