相关论文: Kinematics in Partially Ionised Molecular Clouds: …
Fast magnetic reconnection plays a fundamental role in driving explosive dynamics and heating in the solar chromosphere. The reconnection time scale of traditional models is shortened at the onset of the coalescence instability, which forms…
The existence of substellar cold H2 globules in planetary nebulae and the mere existence of comets suggest that the physics of cold interstellar gas might be much richer than usually envisioned. We study the case of a cold gaseous medium in…
We calculate the evolution of molecular line profiles of HCO$^+$ and C$^{18}$O toward a dense core thatis forming inside a magnetized turbulent molecular cloud. Features of the profiles can be affected more significantly by coupled velocity…
Context: The formation of high-mass star-forming regions from their parental gas cloud and the subsequent fragmentation processes lie at the heart of star formation research. Aims: We aim to study the dynamical and fragmentation properties…
Context. Supersonic disordered flows accompany the formation and evolution of MCs. It has been argued that turbulence can support against gravitational collapse and form hierarchical sub-structures. Aims. We study the time evolution of…
Observations are revealing the ubiquity of filamentary structures in molecular clouds. As cores are often embedded in filaments, it is important to understand how line profiles from such systems differ from those of isolated cores. We…
We study the effects of the initial conditions of turbulent molecular clouds on the ionization structure in newly formed H_{ii} regions, using three-dimensional, photon-conserving radiative transfer in a pre-computed density field from…
Theoretical and observational studies on the turbulence of the interstellar medium developed fast in the past decades. The theory of supersonic magnetized turbulence, as well as the understanding of projection effects of observed…
This is a progress report on our numerical simulations of conditions in the cold cores of cooling flow condensations. The physical conditions in any non-equilibrium plasma are the result of a host of microphysical processes, many involving…
We use numerical hydrodynamic simulations to investigate prestellar core formation in the dynamic environment of giant molecular clouds, focusing on planar post-shock layers produced by colliding turbulent flows. A key goal is to test how…
Kinetic effects in plasma flow due to a finite ion temperature and ion reflections in a converging-diverging magnetic nozzle are investigated with collisionless quasineutral hybrid simulations with kinetic ions and isothermal Boltzmann…
We present results from the first self-consistent multi-fluid simulations of chromospheric magnetic reconnection in a weakly ionized reacting plasma. We simulate two dimensional magnetic reconnection in a Harris current sheet with a…
A fundamental issue in star formation is understanding the precise mechanisms leading to the formation of prestellar cores, and their subsequent gravitationally unstable evolution. To address this question, we carefully construct a suite of…
We derive a mode-coupling theory for the slow dynamics of fluids confined in disordered porous media represented by spherical particles randomly placed in space. Its equations display the usual nonlinear structure met in this theoretical…
{It has recently been proposed that giant molecular complexes form at the sites where streams of diffuse warm atomic gas collide at transonic velocities.} {We study the global statistics of molecular clouds formed by large scale colliding…
A system of inelastic hard disks in a thin pipe capped by hot walls is studied with the aim of investigating velocity correlations between particles. Two effects lead to such correlations: inelastic collisions help to build localized…
Two scenarios have been proposed for evolution of star forming cores: gravitational fragmentation of larger structures and coalescence of smaller entities which are formed from some instabilities. Here, we turn our attention to the latter…
We review the progress that has been made in observing and analyzing molecular cloud structure in recent years. Structures are self-similar over a wide range of scales with similar power law indices independent of the star forming nature of…
Dynamical collapse and fragmentation of low-metallicity cloud cores is studied using three-dimensional hydrodynamical calculations, with particular attention devoted whether the cores fragment in the dust-cooling phase or not. The cores…
We present hydrodynamic simulations of high-velocity clouds (HVCs) traveling through the hot, tenuous medium in the Galactic halo. A suite of models was created using the FLASH hydrodynamics code, sampling various cloud sizes, densities,…