Related papers: Hydrodynamical interaction between an accretion fl…
Dynamical evolution of spiral galaxies is strongly dependent on non-axisymmetric patterns that develop from gravitational instabilities, either spontaneously or externally triggered. Some evolutionary sequences are described through which a…
Galaxy disk formation must incorporate the multiphase nature of the interstellar medium. The resulting two-phase structure is generated and maintained by gravitational instability and supernova energy input, which yield a source of…
The interaction between a protostellar magnetosphere and a surrounding dynamo-active accretion disc is investigated using an axisymmetric mean-field model. In all models investigated, the dynamo-generated magnetic field in the disc arranges…
In the current paradigm of star formation magnetic fields play a very central role. Indeed, they probably help or even channel the initial gravitational collapse of the parent molecular cloud. But their most spectacular effect is certainly…
Selected results from recent studies of star formation in galaxies at different stages of interaction are reviewed. Recent results from the Spitzer Space Telescope are highlighted. Ideas on how large-scale driving of star formation in…
Different hydrodynamic regimes for the gaseous outflows generated by multiple supernovae explosions and stellar winds occurring within compact and massive star clusters are discussed. It is shown that there exists the threshold energy that…
Time-domain spectroscopy of the classical accreting T Tauri star, TW Hya, covering a decade and spanning the far UV to the near-infrared spectral regions can identify the radiation sources, the atmospheric structure produced by…
The current observational evidences suggest there are about hundred billion galaxies in the observable universe and within each, on an average, about hundred billion stars. But no cosmological model indicates as to why there are these many…
Star formation proceeds via the collapse of a molecular cloud core over multiple dynamical timescales. Turbulence within cores results in a spatially non-uniform angular momentum of the cloud, causing a stochastic variation in orientation…
Magnetic flux redistribution lies at the heart of the problem of star formation in dense cores of molecular clouds that are magnetized to a realistic level. If all of the magnetic flux of a typical core were to be dragged into the central…
Major progress has been made over the last few years in understanding hydrodynamical processes on cosmological scales, in particular how galaxies get their baryons. There is increasing recognition that a large part of the baryons accrete…
We investigate, through a series of numerical calculations, the evolution of dense cores that are accreting external gas up to and beyond the point of star formation. Our model clouds are spherical, unmagnetized configurations with fixed…
Sgr A* is currently being fed by winds from a cluster of gravitationally bound young mass-loosing stars. Using observational constraints on the orbits, mass loss rates and wind velocities of these stars, we numerically model the…
We use hydrodynamical simulations of a Cartwheel-like ring galaxy, modelled as a nearly head-on collision of a small companion with a larger disc galaxy, to probe the evolution of the gaseous structures and flows, and to explore the…
Here we discuss the interaction of massive stars with their parental molecular clouds. A summary of the dynamical evolution of HII regions and wind-driven bubbles in high-pressure cloud cores is given. Both ultracompact HII regions and…
We have used a coupled dynamical and chemical model to examine the chemical changes induced by the passage of an interstellar shock in well shielded regions. Using this model we demonstrate that the formation of water in a shock will be…
We discuss star formation in the turbulent interstellar medium. We argue that morphological appearance and dynamical evolution of the gas is primarily determined by supersonic turbulence, and that stars form via a process we call…
We present the main features in the evolution of the gas pressure in star forming regions, from the formation of the parental cloud to the moment when the region is pressurized by interacting stellar winds. The main processes for cloud…
The time of protostellar wind breakout may be determined by the evolution of the infalling flow, rather than any sudden change in the central engine. I examine the transition from pure infall to outflow, in the context of the inside-out…
We perform numerical simulations to investigate the stellar wind from interacting binary stars. Our aim is to find analytical formulae describing the outflow structure. In each binary system the more massive star is in the asymptotic giant…