Abstracts
"A Systematic Approach to Studying Galaxy Cluster Formation in the Early Universe"
Observations of massive galaxy clusters have shown that the overall
cluster properties evolved very little since z < 1-2. Stellar
populations of the cluster red sequence are old, with implied
formation redshifts of z ~ 2-4. To understand how these galaxy clusters
form and how their overdense environments influence galaxy evolution,
it is crucial to probe the epoch of cluster formation at 2 < z < 5. With
the ultimate goal of building a roadmap for interpreting future
surveys like HETDEX, we are performing a statistical,
simulations-assisted study of (proto-)cluster evolution. We use the
LCDM predictions for dark matter and accurate semi-analytic models for
galaxies to quantify the relations between galaxy clusters and
overdensities in the distributions of the dark matter, halos, and
galaxies as a function of, e.g., redshift and galaxy type. We model
the selection and projection effects as found in observational surveys
even more accurately by using lightcones and simulated data. We use
our simulations predictions to interpret observations of a range of
structures found at z > 2, and to make feasibility predictions for
future experiments. |
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"A Systematic Approach to Studying Galaxy Cluster Formation in the Early Universe"
In this talk I present the first results from The X-Shooter Lens Survey (X-LENS). |
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"Scalar Fields as Dark Matter in the Universe"
In the last time the cold dark matter (CDM) model faces some difficulties to describe all the properties of nearby galaxies that can be observed in great detail as well as that it has some problems in the mechanism by which matter is more rapidly gathered into large-scale structure such as galaxies and clusters of galaxies. In this talk we review the scalar field dark matter (SFDM) model, which proposes that the galactic haloes form by condensation of a scalar field (SF) very early in the Universe, i.e., in this model the haloes of galaxies are astronomical Bose-Einstein Condensate drops of SF. On the other hand, large-scale structures like clusters or superclusters of galaxies form similar to the CDM model, by hierarchy, thus all the predictions of the CDM model at cosmological scales are reproduced by SFDM. This model predicts that all galaxy haloes must be very similar and exist for higher redshifts than in the CDM model. |