相关论文: Collapse and Fragmentation in Finite Sheets

The onset of star formation is set by the collapse of filaments in the interstellar medium. From a theoretical point of view, an isolated cylindrical filament forms cores via the edge effect. Due to the self-gravity of a filament, the…

The study of star cluster evolution necessitates modeling how their density profiles develop from their natal gas distribution. Observational evidence indicates that many star clusters follow a Plummer-like density profile. However, most…

We investigate, using 3D hydrodynamic simulations, the fragmentation of pressure-confined, vertically stratified, self-gravitating gaseous layers. The confining pressure is either thermal pressure acting on both surfaces, or thermal…

We study the linear evolution of small perturbations in self-gravitating fluid systems in two spatial dimensions; we consider both cylindrical and cartesian (i.e., slab) geometries. The treatment is general, but the application is to…

We study the collapse and virialization of an isolated spherical cloud of self-gravitating particles initially at rest and characterised by a power-law density profile, with exponent 0<= \alpha < 3, or by a Plummer, an Hernquist, a NFW, a…

Motivated by the nonlinear star formation efficiency found in recent numerical simulations by a number of workers, we perform high-resolution adaptive mesh refinement simulations of star formation in self-gravitating turbulently driven gas.…

This paper deals with a detail study of gravitational collapse of dust and viscous fluids under the assumptions of spherical symmetry. Our main goal is to closely analyze the horizons which arise during this gravitational phenomenon. To…

Galaxy surveys provide finite catalogs of objects observed within bounded volumes, yet clustering statistics are often interpreted using theoretical frameworks developed for infinite point processes. In this work, we formulate key…

We construct a filament catalogue using an extension of the halo based filament finder of Zhang et al.(2009), in a 250 Mpc/h side N-body simulation, and study the properties of filaments ending upon or surrounding galaxy clusters (within 10…

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…

Soft-granular media, such as dense emulsions, foams or tissues, exhibit either fluid- or solid-like properties depending on the applied external stresses. Whereas bulk rheology of such materials has been thoroughly investigated, the…

Stars are thought to form predominantly within filamentary molecular clouds. Recent studies have suggested that active star formation, including the formation of stellar clusters and massive stars, occurs within so-called "hub" structures,…

We present numerical simulations of the passage of clumpy gas through a galactic spiral shock and the subsequent formation of giant molecular clouds (GMCs). The spiral shock forms dense clouds while dissipating kinetic energy, producing…

We examined the gravitational contraction of isothermal molecular cloud cores with slow rotation by means of two-dimensional numerical simulations. Applying a sink-cell method, we followed the evolution of the cloud cores up to the stages…

According to the latest evidence, the Universe is entering an era of exponential expansion, where gravitationally bound structures will get disconnected from each other, forming isolated `island universes'. In this scenario, we present a…

I present the first analytical study of gravitational collapse in a compact CMC foliation with $S^3$ spatial topology. The solutions I find, in this context, will be both solutions of Shape Dynamics and General Relativity. The aim is to…

We will describe here the structure of singularity forming in gravitational collapse of spherically symmetric inhomogeneous dust. Such a collapse is described by the Tolman-Bondi-Lema{\^i}tre metric. The main new result here relates, in a…

In order to develop a complete theory of star formation, one essentially needs to know two things: what collapses, and how long it takes. This is the second paper in a series, where we query how long a parcel of gas takes to collapse and…

In this paper we study the gravitational collapse of a molecular hydrogen gas cloud composed of a core plus a gas envelope surrounding the core. We numerically simulate the collapse of four cloud models to take a glimpse to the time…

The formation of self-gravitating systems is studied by simulating the collapse of a set of N particles which are generated from several distribution functions. We first establish that the results of such simulations depend on N for small…