Analyse multi-longueur d'onde d'amas de galaxies en coalescence

Abstract : In the framework of the hierarchical model of structure formation,
galaxy clusters are supposed to form by accretion and merging of
smaller units.

I present our multi-wavelength (optical, X-ray and radio) observation program of a sample of morphologically complex clusters, representing the different phases of the merging process ("MUSIC: MUlti-wavelength Sample of Interacting Clusters"). This program aims to characterize the formation and evolution phases of interacting clusters. Multi-wavelength analysis is an essential tool to understand these complex systems, as it allows to follow the evolution of its various components: galaxies (optical observations), gas (X-ray observations) and non-thermal components (i.e. relativistic particles and magnetic field emitting at radio wavelengths).

In the first part of this thesis, the current knowledge about the
physics of merging cluster is detailed by comparing the main
observational results with the predictions of numerical simulations.

The observations and the data reduction techniques performed in our
program are presented in the second part. Following the expectations of the hierarchical model of structure formation, our results on the first clusters of our sample show that they are currently forming by the merging of their sub-structures. These clusters form a sequence from pre-merging (A1750) to post-merging systems (A1413), with A3921 and A521 observed in the central phases of sub-clusters collision. The large scale environment of merging clusters, and the effects of the merger event both on their dynamics and on the internal properties of their galaxies are introduced and discussed in the enclosed papers.
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https://tel.archives-ouvertes.fr/tel-00010416
Contributor : Chiara Ferrari <>
Submitted on : Thursday, October 6, 2005 - 11:44:26 AM
Last modification on : Sunday, December 23, 2018 - 1:20:10 AM
Long-term archiving on: Wednesday, March 29, 2017 - 11:58:18 AM

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  • HAL Id : tel-00010416, version 2

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Chiara Ferrari. Analyse multi-longueur d'onde d'amas de galaxies en coalescence. Astrophysique [astro-ph]. Université Nice Sophia Antipolis, 2003. Français. ⟨tel-00010416v2⟩

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