相关论文: Self-similar champagne flows in HII regions

We study the structural evolution of turbulent molecular clouds under the influence of ionizing radiation emitted from a nearby massive star by performing a high resolution parameter study with the iVINE code. The temperature is taken to be…

The origin of rovibrational H_2 emission in the central galaxies of cooling flow clusters is poorly understood. Here we address this issue using data from our near-infrared spectroscopic survey of 32 of the most line luminous such systems,…

It is argued that galaxies like ours sustain their star formation by transferring gas from an extensive corona to the star-forming disc. The transfer is effected by the galactic fountain -- cool clouds that are shot up from the plane to…

Using a suite of radiation hydrodynamic simulations of star cluster formation in turbulent clouds, we study the escape fraction of ionizing (Lyman continuum) and non-ionizing (FUV) radiation for a wide range of cloud masses and sizes. The…

Ultracompact and hypercompact HII regions appear when a star with a mass larger than about 15 solar masses starts to ionize its own environment. Recent observations of time variability in these objects are one of the pieces of evidence that…

We study closed dense collections of hard spheres that collide inelastically with constant coefficient of normal restitution. We find inhomogeneous states (IS) where the density profile is spatially non-uniform but constant in time. The…

The hypothesis that massive stars form by accretion can be investigated by simple analytical calculations that describe the effect that the formation of a massive star has on its own accretion flow. Within a simple accretion model that…

We present new observations of [CII] fine structure line emission from an isolated molecular cloud using the upGREAT instrument onboard SOFIA. These data are analyzed together with archival CO=1-0 and HI 21 cm emission spectra to…

Because of the negative inclination of the solid-liquid phase separation line in water, ice Ih melts on compression. On further increase in pressure the liquid water transforms into a high density metastable glassy state, characterized by a…

We have reexamined the similarity solution for a self-gravitating isothermal gas sphere and examined implication to star formation in a turbulent cloud. When parameters are adequately chosen, the similarity solution expresses an accreting…

We study the expansion of the ionization and dissociation fronts (DFs) in a radially stratified molecular cloud, whose density distribution is represented as n(r) \propto r^-w. We focus on cases with w \leq 1.5, when the ionization front is…

(Abridged) We present numerical hydrodynamical simulations of the formation, evolution and gravitational collapse of isothermal molecular cloud cores. A compressive wave is set up in a constant sub-Jeans density distribution of radius r = 1…

We investigate the thermodynamics of the ISM and the formation of molecular hydrogen through numerical simulations of spiral galaxies. The model follows the chemical, thermal and dynamical response of the disc to an external spiral…

We present a study of diffuse extended ionised gas toward three clouds located in the Galactic Centre (GC). One line of sight (LOS) is toward the 20 km s$^{-1}$ cloud (LOS$-$0.11) in the Sgr A region, another LOS is toward the 50 km…

We present general properties of ionized hydrogen (HII) bubbles and their growth based on a state-of-the-art large-scale (100 Mpc/h) cosmological radiative transfer simulation. The simulation resolves all halos with atomic cooling at the…

Spatially homogeneous thermal equilibria of self-gravitating gas, being impossible otherwise, are nevertheless allowed in an expanding background accounting for Universe's expansion. Furthermore, a fixed density at the boundary of a…

Molecular clouds, which harbor the birthplaces of stars, form out of the atomic phase of the interstellar medium (ISM). We aim to characterize the atomic and molecular phases of the ISM and set their physical properties into the context of…

We study the molecular and the ionized gas in a possible precursor of an UC HII region to contribute to the understanding of how high-mass stars build-up their masses once they have reached the zero-age main secuence. We carried out…

We aim to investigate the chemistry of internal photon-dominated regions surrounding deeply embedded hypercompact and ultracompact HII regions. We search for specific tracers of this evolutionary stage of massive star formation that can be…

We simulate the multi-phase interstellar medium randomly heated and stirred by supernovae, with gravity, differential rotation and other parameters of the solar neighbourhood. Here we describe in detail both numerical and physical aspects…