Contributions
This site provides detailed information about the contributions made to the GG2014. If you want to give a talk or present a poster in our mini-workshop, just click
here.
Last update: September 05, 2014. 10:08:17
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1. Mariano Dominguez. Institute for Theoretical and Experimental Astronomy . Argentina.
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Contribution : Talk
Title : Merging Systems Identification in Systems of Galaxies
Abstract
The Bullet Cluster and many other examples of merging systems provided
observational evidence for the existence of dark matter.
Most of them have been used to test the Cold Dark Matter (CDM)
paradigm itself. The presence of DM and constraints on its
self-interaction cross section can therefore be inferred by
measuring a spatial offset between the X-ray emission of the
ICM plasma and its total mass distribution.
Using a combination of test (Dressler Schectman (1988) and Mixture of Gaussians)
designed to detect substructures, we are able to define samples of merging
systems with high levels of completitude, low contamination and almost exact
definition of the center position. Using simulated SDSS galaxy catalogs
we could known under which conditions our algorithms identify real
mergers and therefore avoid false substructures identifications in
real catalogs.
Our uniform samples allow us to study the DM properties using kinematical analysis combined with X-ray observations and Weak Lensing mass reconstruccion (currently under way)
2. Mischa Shirmer . Gemini Observatory, South Operation Center, Chile.
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Contribution : Talk
Title : To confirm
Abstract
Fossil groups of galaxies represent the latest stage of mass assembly in the Universe, possibly forming the predecessors of brightest cluster galaxies (BCGs). The brightest galaxy in the fossil group J0454-0309 strongly lenses a distant background galaxy. Combining the asymmetric image configuration, weak lensing, X-ray and velocity data, I show that it did not form at the current center of the gravitational potential. Instead, it is injected into a larger structure, confirming the idea that future BCGs indeed may have formed first in groups.
3. German Gimeno . Gemini Observatory, South Operation Center, Chile.
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Contribution : Poster
Title : To confirm
Abstract
Soon more information
4. Jonathan D. Hernandez-Fernandez . Universidade de Sao Paulo, Brasil.
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Contribution : Talk
Title : To confirm
Abstract
(preliminary) We have recently identified a local sample of 280 compact Star-Forming Groups (SFGs) of galaxies in the ultraviolet GALEX AIS catalogue. The sample, new reduced data and observations of some SFGs will be presented.
5. Geroge Hou . European Southern Observatories.
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Contribution : Talk
Title : To confirm
Abstract
(preliminary) I will present a talk on MUSE observations ram-pressure stripped galaxies in clusters, or on the kinematics of shell galaxies in isolated or group environments.
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6. Catrina Diener . European Southern Observatories.
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Contribution : Talk
Title : To confirm
Abstract
The zCOSMOS-deep survey contains 3500 galaxies with spectroscopic redshifts between 2<z<3. We devised a group-finder that takes into account the large measurement uncertainties at this redshift and identified 42 proto-groups at 2<z<3, allowing a statistical approach to the properties of such systems. I will discuss the evolution of these proto-groups as seen in simulations as well as how the proto-group environment impacts on galaxy properties. A special focus will lie on a z=2.5 proto-cluster, one of the most distant structures identified, with (to date) 11 spectroscopically confirmed members. The spectroscopic data for this system are complemented by UVISTA, COSMOS and Ha coverage (VLT/ISAAC). It therefore provides an interesting insight into how high-z extreme environments impact the star-formation rates and the masses of the member galaxies and permits the study of the first signatures of environmental differentiation. We contrast this finding with a theoretical perspective, by appealing to various semi-analytic models of galaxy formation. By comparing the evolution of synthetic galaxies against our observations, we can draw conclusions as to the validity of these models.
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