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Kinematic Properties and Stellar Populations of Faint Early-Type Galaxies. I. Velocity Dispersion Measurements of Central Coma Galaxies

Ana Matkovic·Rafael Guzman
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Abstract

We present velocity dispersion measurements for 69 faint early-type galaxies in the core of the Coma cluster, spanning -22.0<M_R<-17.5 mag. We examine the L-σrelation for our sample and compare it to that of bright ellipticals from the literature. The distribution of the the faint early-type galaxies in the L-sigma plane follows the relation L ~ σ^{2.01\pm0.36}, which is significantly shallower from L ~ σ^4 as defined for the bright ellipticals. While increased rotational support for fainter early-type galaxies could account for some of the difference in slope, we show that it cannot explain it. We also investigate the Colour-σrelation for our Coma galaxies. Using the scatter in this relation, we constrain the range of galaxy ages as a function of their formation epoch for different formation scenarios. Assuming a strong coordination in the formation epoch of faint early-type systems in Coma, we find that most had to be formed at least 6 Gyrs ago and over a short 1 Gyr period.

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Ana Matkovic, Rafael Guzman. 2005-06-22. Kinematic Properties and Stellar Populations of Faint Early-Type Galaxies. I. Velocity Dispersion Measurements of Central Coma Galaxies. https://doi.org/10.1111/j.1365-2966.2005.09298.x

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