相关论文: Resolving the Formation of Protogalaxies. II. Cent…
To constrain the nature of the very first stars, we investigate the collapse and fragmentation of primordial, metal-free gas clouds. We explore the physics of primordial star formation by means of three-dimensional simulations of the dark…
The standard model of gravitational structure formation is based on the Jeans 1902 acoustic theory, neglecting crucial effects of viscosity, turbulence and diffusion. A Jeans length scale L_J emerges that exceeds the scale of causal…
We discuss early results from the first large N-body/hydrodynamical simulation to resolve the formation of galaxies in a cold dark matter universe. The simulation follows the formation of galaxies by gas cooling within dark halos of mass a…
Cosmic structure originated from minute density perturbations in an almost homogeneous universe. The first stars are believed to be very massive and luminous, providing the first ionizing radiation and heavy elements to the universe and…
The standard model of gravitational structure formation is based on the Jeans 1902 acoustic theory, neglecting nonlinear instabilities controlled by viscosity, turbulence and diffusion. Because the Jeans scale L_J for the hot primordial…
Using three-dimensional cosmological simulations, we study the assembly process of one of the first galaxies, with a total mass of 10^8 M_sun, collapsing at z = 10. Our main goal is to trace the transport of the heavy chemical elements…
We present results of large N-body-hydrodynamic simulations of galaxy formation. Our simulations follow the formation of galaxies in cubic volumes of side 100Mpc, in two versions of the cold dark matter (CDM) cosmogony: the standard,…
High resolution gravity plus smoothed particle hydrodynamics simulations are used to study the formation of galaxies within the context of hierarchical structure formation. The simulations have sufficient dynamic range to resolve from ten…
(abridged) We use large cosmological simulations to study the origin of primordial star-forming clouds in a Lambda CDM universe, by following the formation of dark matter halos and the cooling of gas within them. To model the physics of…
We trace the evolution of central galaxies in three ~10^13 M_sun galaxy groups simulated at high resolution in cosmological hydrodynamical simulations. The evolution in the group potential leads, at z=0, to central galaxies that are…
We investigate the properties of the first galaxies at z > 10 with highly resolved numerical simulations, starting from cosmological initial conditions and taking into account all relevant primordial chemistry and cooling. A first galaxy is…
We compute, including a current state-of-the-art treatment of hydrodynamical processes, heating and cooling, a variety of cosmological models into the extreme nonlinear phase to enable comparisons with observations. First, we note the…
The formation of the first galaxies at redshifts z~10-15 signaled the transition from the simple initial state of the universe to one of ever increasing complexity. We here review recent progress in understanding their assembly process with…
(Abridged) Galaxies form in hierarchically assembling dark matter halos. With cosmological three dimensional adaptive mesh refinement simulations, we explore in detail the virialization of baryons in the concordance cosmology, including…
Many questions in physical cosmology regarding the thermal history of the intergalactic medium, chemical enrichment, reionization, etc. are thought to be intimately related to the nature and evolution of pregalactic structure. In particular…
We investigate the early formation of bound objects with masses comparable to the cosmological Jeans mass (10^5 solar masses). We follow the growth of isolated spherically symmetric density peaks starting from the linear perturbative…
Using hydrodynamic simulations we investigate the time evolution and fragmentation of regions within molecular clouds which have lost their turbulent support leading to gravitational contraction. The initial density distributions are…
In order to constrain the initial mass function (IMF) of the first generation of stars (Population III), we investigate the fragmentation properties of metal-free gas in the context of a hierarchical model of structure formation. We…
We study the gravitational fragmentation of cold accretion streams flowing into a typical first galaxy. We use a one-zone hydrodynamical model to examine the thermal evolution of the gas entering a 10^8 M_sun DM halo at z=10. The goal is to…
The formation of quasar black holes during the hydrodynamic collapse of protogalactic gas clouds is discussed. The dissipational collapse and long- term dynamical evolution of these systems is analysed using three-dimensional numerical…