Mild Velocity Dispersion Evolution of Spheroid-Like Massive Galaxies Since z ~ 2

Cenarro, A. Javier; Trujillo, I.
Bibliographical reference

The Astrophysical Journal Letters, Volume 696, Issue 1, pp. L43-L47 (2009).

Advertised on:
5
2009
Number of authors
2
IAC number of authors
2
Citations
114
Refereed citations
104
Description
Making use of public spectra from Cimatti et al., we measure for the first time the velocity dispersion of spheroid-like massive (M sstarf ~ 1011 M sun) galaxies at z ~ 1.6. By comparing with galaxies of similar stellar mass at lower redshifts, we find evidence for a mild evolution in velocity dispersion, decreasing from ~240 km s-1 at z ~ 1.6 down to ~180 km s-1 at z ~ 0. Such mild evolution contrasts with the strong change in size (a factor of ~4) found for these type of objects in the same cosmic time, and it is consistent with a progressive larger role, at lower redshift, of the dark matter halo in setting the velocity dispersion of these galaxies. We discuss the implications of our results within the context of different scenarios proposed for the evolution of these massive objects.
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Traces of Galaxy Formation: Stellar populations, Dynamics and Morphology
We are a large, diverse, and very active research group aiming to provide a comprehensive picture for the formation of galaxies in the Universe. Rooted in detailed stellar population analysis, we are constantly exploring and developing new tools and ideas to understand how galaxies came to be what we now observe.
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