Related papers: Entropy generation in merging galaxy clusters
It is widely believed that structure in the Universe evolves hierarchically, as primordial density fluctuations, amplified by gravity, collapse and merge to form progressively larger systems. The structure and evolution of X-ray clusters,…
Particles dropped into a rotating black hole can collide near the inner horizon with enormous energies. The entropy produced by these collisions can be several times larger than the increase in the horizon entropy due to the addition of the…
Clusters of galaxies are studied from a theoretical point of view, comparing with observational results whenever possible. The problem is approached both analytically as well as by means of high-resoultion numerical simulations. The dark…
Galaxy clusters form from the infall of dark and baryonic matter at the intersection of cosmic filaments. Most of the baryons are in the form of a hot, magnetized, intracluster plasma detected through its X-ray thermal bremsstrahlung…
Several physical processes and formation events are expected in cluster outskirts, a vast region up to now essentially not covered by observations. The recent Suzaku (X-ray) and Planck (Sunayev-Zeldovich effect) observations out to the…
Semi-analytic models of X-ray clusters and groups of galaxies, relying on the idea that there was a non-gravitational energy injection in these systems, are able to reproduce many observed correlations, in particular the L_X-T relation and…
The physical processes that define the spine of the galaxy cluster X-ray luminosity -- temperature (L-T) relation are investigated using a large hydrodynamical simulation of the Universe. This simulation models the same volume and phases as…
We develop a model to describe the evolution of the intra-cluster X-ray emitting baryons, as they are included in the dark matter potential wells of galaxy clusters evolving through subsequent merging events in the framework of hierarchical…
In the current galaxy formation scenarios, two physical phenomena are invoked to build disk galaxies: hierarchical mergers and more quiescent external gas accretion, coming from intergalactic filaments. Although both are thought to play a…
Star formation in the universe's largest galaxies---the ones at the centers of galaxy clusters---depends critically on the thermodynamic state of their hot gaseous atmospheres. Central galaxies with low-entropy, high-density atmospheres…
Using adiabatic hydrodynamical simulations, we follow the evolution of two symmetric cold fronts developing in the remnant of a violent z=0.3 massive cluster merger. The structure and location of the simulated cold fronts are very similar…
The physical mechanisms and timescales that determine the morphological signatures and the quenching of star formation of typical (~L*) elliptical galaxies are not well understood. To address this issue, we have simulated the formation of a…
Collisions and mergers of gas-rich galaxies trigger bursts of star and cluster formation. Of the thousands of clusters typically formed during a major merger, only the most massive and compact survive for Gigayears as globular clusters…
Young, massive star clusters are the most notable and significant end products of violent star-forming episodes triggered by galaxy collisions, mergers, and close encounters. Their contribution to the total luminosity induced by such…
We review recent progress in the description of the formation and evolution of galaxy clusters in a cosmological context by using numerical simulations. We focus our presentation on the comparison between simulated and observed X-ray…
A review of gravitational and hydrodynamical processes during formation of clusters and evolution of galaxies is given. Early, at the advent of N-body computer simulations, the importance of tidal fields in galaxy encounters has been…
Nuclear Clusters (NCs) are common stellar systems in the centres of galaxies. Yet, the physical mechanisms involved in their formation are still debated. Using a parsec-resolution hydrodynamical simulation of a dwarf galaxy, we propose an…
Aims. We aim to provide constraints on evolutionary scenarios in clusters. One of our main goals is to understand whether, as claimed by some, the cool core/non-cool core division is established once and for all during the early history of…
We report the results of our study of fractional entropy enhancement in the intra-cluster medium (ICM) of the clusters from the representative XMM-Newton cluster structure survey (REXCESS). We compare the observed entropy profile of these…
We use a simple hard-core gas model to study the dynamics of small exploding systems. The system is initially prepared in a thermalized state in a spherical container and then allowed to expand freely into the vacuum. We follow the…