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arXiv · 1107.4640

Velocity Dispersions and Stellar Populations of the Most Compact and Massive Early-Type Galaxies at Redshift ~1

Jesus Martinez-Manso·Rafael Guzman·Guillermo Barro·Javier Cenarro·Pablo Perez-Gonzalez·Patricia Sanchez-Blazquez·Ignacio Trujillo·Marc Balcells·Nicolas Cardiel·Jesus Gallego·Angela Hempel·Mercedes Prieto
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Abstract

We present Gran-Telescopio-Canarias/OSIRIS optical spectra of 4 of the most compact and massive early-type galaxies in the Groth Strip Survey at redshift z~1, with effective radii Reff=0.5-2.4 kpc and photometric stellar masses Mstar=1.2-4x10^11 Msun. We find these galaxies have velocity dispersions sigma=156-236 km/s. The spectra are well fitted by single stellar population models with approximately 1 Gyr of age and solar metallicity. We find that: i) the dynamical masses of these galaxies are systematically smaller by a factor of ~6 than the published stellar masses using BRIJK photometry; ii) when estimating stellar masses as 0.7xMdyn, a combination of passive luminosity fading with mass/size growth due to minor mergers can plausibly evolve our objects to match the properties of the local population of early-type galaxies.

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Jesus Martinez-Manso, Rafael Guzman, Guillermo Barro, Javier Cenarro, Pablo Perez-Gonzalez, Patricia Sanchez-Blazquez, Ignacio Trujillo, Marc Balcells, Nicolas Cardiel, Jesus Gallego, Angela Hempel, Mercedes Prieto. 2011-07-22. Velocity Dispersions and Stellar Populations of the Most Compact and Massive Early-Type Galaxies at Redshift ~1. https://doi.org/10.1088/2041-8205%2F738%2F2%2Fl22

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