相关论文: Dynamics of Stellar Collisions
We review a series of recent results on global dynamic properties of radially symmetric self-gravitating compressible Euler flows, which naturally arise in the mathematical description of stars. We focus on the role of scaling invariances…
Two competing models, gravitational instability-driven transport and stellar feedback, have been proposed to interpret the high velocity dispersions observed in high-redshift galaxies. We study the major mechanisms to drive the turbulence…
Accumulation of new data on stellar hierarchical systems and the progress in numerical simulations of their formation open the door to genetic classification of these systems, where properties of a certain group (family) of objects are…
We use numerical simulations to study the development of gas/star offsets in the tidal tails of merging galaxies. These offsets are shown to be a natural consequence of the radially extended HI spatial distribution in disk galaxies, coupled…
2D axis-symmetric hydrodynamical simulations are presented which explore the interaction of stellar and disk winds with surrounding infalling cloud material. The star, and its accompanying disk, blow winds inside a cavity cleared out by an…
A large class of stellar systems (e.g., planetary nebulae (PNe), supernova envelopes, LBV stars, young stars in formation) shows structures in their accretion/ejection phase that have similar characteristics. In particular, one currently…
The effects of rapid rotation on stellar evolution can be profound. We are now beginning to gather enough data to allow a realistic comparison between different physical models. Two key tests for any theory of stellar rotation are first…
Chemo-dynamical models have been introduced in the late eighties and are a generally accepted tool for understanding galaxy evolution. They have been successfully applied to one-dimensional problems, e.g. the evolution of non-rotating…
This chapter reviews the dynamical processes in young stellar clusters. The accretion of gas by individual stars affects the dynamics of the cluster, and the masses of the stars. Dynamical mass segregation cannot explain the degree of mass…
Galactic accretion interacts in complex ways with gaseous halos, including galactic winds. As a result, observational diagnostics typically probe a range of intertwined physical phenomena. Because of this complexity, cosmological…
The dynamical stability and evolution of disc galaxies with different disc thickness as well as various fraction and concentration of stellar counter-rotation is investigated with self-consistent numerical simulations. In particular,…
Globular clusters are collisional systems, meaning that the stars inside them interact on timescales much shorter than the age of the Universe. These frequent interactions transfer energy between stars and set up observable trends that tell…
Stars are fossils that retain the history of their host galaxies. Elements heavier than helium are created inside stars and are ejected when they die. From the spatial distribution of elements in galaxies, it is therefore possible to…
We use a state-of-the-art semi-analytic model to study the size and the specific angular momentum of galaxies. Our model includes a specific treatment for the angular momentum exchange between different galactic components. Disk scale radii…
The search for thermodynamic admissibility moreover reveals a fundamental difference between liquids and gases in relativistic fluid dynamics, as the reversible convection mechanism is much simpler for liquids than for gases. In…
The Euler equations of ideal gas dynamics posess a remarkable nonlinear involutional symmetry which allows one to factor out an arbitrary uniform expansion or contraction of the system. The nature of this symmetry (called by cosmologists…
We develop a physical model for how galactic disks survive and/or are destroyed in interactions. Based on dynamical arguments, we show gas primarily loses angular momentum to internal torques in a merger. Gas within some characteristic…
This thesis embraces several aspects of theoretical stellar dynamics in clusters, both analytically and numerically. We try to elucidate the phenomena currently observed in all types of galaxies, including AGNs and quasars, some of the most…
Galaxy evolution depends strongly on the environment. Dynamical interactions and subsequent evolution make galaxies more concentrated, with higher surface densities, and also trigger star-formation, which consumes the available cold gas.…
Observations and cosmological simulations indicate that the early Universe hosted numerous compact, high-density stellar systems, where close encounters and physical collisions between stars were likely common. We develop a bottom-up…