相关论文: Beyond Inside-Out Growth: Formation and Evolution …
We investigate the dissolution process of young embedded star clusters with different primordial mass segregation levels using fractal distributions by means of N-body simulations. We combine several star clusters in virial and subvirial…
A standard paradigm is now available for the recent evolution (z < 10) of structure on galactic and larger scales. Most of the matter is assumed to be dark and dissipationless and to cluster hierarchically from gaussian initial conditions.…
When density fluctuations collapse gravitationally out of the expanding cosmological background universe to form galaxies, the secondary energy release which results can affect their subsequent evolution profoundly. We focus here on the…
Using high resolution N-body simulations of stellar disks embedded in cosmologically motivated dark matter halos, we study the evolution of bars and the transfer of angular momentum between halos and bars. We find that dynamical friction…
The assembly of galaxies can be described by the distribution of their star formation as a function of cosmic time. Thanks to the WFC3 grism on HST it is now possible to measure this beyond the local Universe. Here we present the spatial…
Most stars in the Galaxy are believed to be formed within star clusters from collapsing molecular clouds. However, the complete process of star formation, from the parent cloud to a gas-free star cluster, is still poorly understood. We…
Here we explore the evolution of galaxy ensembles at early times by writing the in situ stellar mass growth of galaxies purely as a stationary stochastic (e.g., quasi-steady state) process. By combining the mathematics of such processes…
We develop a new realistic prescription for modeling the stellar feedback, which minimizes any ad hoc assumptions about sub-grid physics. We start with developing high resolution models of the ISM and formulate the conditions required for…
We have performed hydrodynamic simulations of galaxy formation in a LCDM universe. We have followed galaxy formation in a dark matter halo, chosen to have a relatively quiet recent merger history, using different models for star formation…
A new idea is proposed for the origin of bulges in spiral galaxies. Numerical simulations for the protogalactic collapse suggest strongly that galactic bulges have been assembled from massive clumps formed in the galactic disks in their…
Observations of disk galaxies at z~2 have demonstrated that turbulence driven by gravitational instability can dominate the energetics of the disk. We present a 1D simulation code, which we have made publicly available, that economically…
We present a theoretical model for primordial star formation. First we describe the structure of the initial gas cores as virialized, quasi-hydrostatic objects in accord with recent high resolution numerical studies. The accretion rate can…
Quantification of the Galaxy's star formation history involves both the duration and the rate of formation, with these parameters being known with different precision for different populations. The early rate of star formation is knowable…
Substantial numbers of morphologically regular early-type (elliptical and lenticular) galaxies contain molecular gas, and the quantities of gas are probably sufficient to explain recent estimates of the current level of star formation…
(Abridged) High redshift galaxies are undergoing intensive evolution of dynamical structure and morphologies. We incorporate the feedback into the dynamical equations through mass dropout and angular momentum transportation driven by the…
Stars mostly form in groups consisting of a few dozen to several ten thousand members. For 30 years, theoretical models provide a basic concept of how such star clusters form and develop: they originate from the gas and dust of collapsing…
We investigate a model in which galactic nuclei form via the coalescence of pre-existing stellar systems containing supermassive black holes. Merger simulations are carried out using N-body algorithms that can follow the formation and decay…
Planets are born from the gas and dust discs surrounding young stars. Energetic radiation from the central star can drive thermal outflows from the discs atmospheres, strongly affecting the evolution of the discs and the nascent planetary…
We discuss the evolution of a disc galaxy due to the formation of a bar and, subsequently, a peanut. After the formation stage there is still considerable evolution, albeit slower. In purely stellar cases the pattern speed of the bar…
We carry out a detailed orbit analysis of gravitational potentials selected at different times from an evolving self-consistent model galaxy consisting of a two-component disk (stars+gas) and a live halo. The results are compared with a…