相关论文: Hydro-chemical study of the evolution of interstel…
Within the precise cosmological framework provided by the Lambda-Cold Dark Matter model and standard Big Bang nucleosynthesis, the chemical evolution of the pregalactic gas can now be followed with accuracy limited only by the uncertainties…
The collapse of dense cores with different metallicities is studied by hydrodynamical calculations coupled with detailed chemical and radiative processes. For this purpose, we construct a simple chemical network with non-equilibrium…
Studies of the evolution of massive protostars and the evolution of their host molecular cloud cores are commonly treated as separate problems. However, interdependencies between the two can be significant. Here, we study the simultaneous…
Context: Chemical models of dense cloud cores often utilize the so-called pseudo-time-dependent approximation, in which the physical conditions are held fixed and uniform as the chemistry occurs. In this approximation, the initial…
Extremely large deuteration of several molecules has been observed towards prestellar cores and low-mass protostars for a decade. New observations performed towards low-mass protostars suggest that water presents a lower deuteration in the…
The past century of interstellar dust has brought us from first ignoring it to finding that it plays an important role in the evolution of galaxies. Current observational results in our galaxy provide a complex physical and chemical…
In this paper we adopt a chemical evolution model, which is an improved version of the Chiappini, Matteucci and Gratton (1997) model, assuming two main accretion episodes for the formation of the Galaxy. The present model takes into account…
We report results from radiation hydrodynamical simulations of the collapse of molecular cloud cores to form protostars. The calculations follow the formation and evolution of the first hydrostatic core/disc, the collapse to form a stellar…
The abundance evolution of interstellar dust species originating from stellar sources and from condensation in molecular clouds in the local interstellar medium of the Milky Way is studied and the input of dust material to the Solar System…
(Abridged) Exoplanet atmospheres are thought be built up from accretion of gas as well as pebbles and planetesimals in the midplanes of planet-forming disks. The chemical composition of this material is usually assumed to be unchanged…
Star formation is intimately linked to the dynamical evolution of molecular clouds. Turbulent fragmentation determines where and when protostellar cores form, and how they contract and grow in mass via accretion from the surrounding cloud…
The latest developments in astrochemistry have shown how some molecular species can be used as a tool to study the early stages of the solar-type star formation process. Among them, the more relevant species are the interstellar complex…
Contemporary galactic star formation occurs predominantly within gravitationally unstable, cold, dense molecular gas within supersonic, turbulent, magnetized giant molecular clouds (GMCs). Significantly, because the chemical evolution…
The molecular evolution that occurs in collapsing prestellar cores is investigated. To model the dynamics, we adopt the Larson-Penston (L-P) solution and analogues with slower rates of collapse. For the chemistry, we utilize the new…
Understanding the collapse of dense molecular cloud cores to stellar densities and the subsequent evolution of the protostar is of importance to model the feedback effects such an object has on its surrounding environment, as well as…
Much of what we know about molecular clouds, and by extension star formation, comes from molecular line observations. Interpreting these correctly requires knowledge of the underlying molecular abundances. Simulations of molecular clouds…
The transformation of atomic hydrogen to molecular hydrogen through three-body reactions is a crucial stage in the collapse of primordial, metal-free halos, where the first generation of stars (Population III stars) in the Universe are…
In this paper we review recent progress in our understanding of the chemical evolution of protoplanetary disks. Current observational constraints and theoretical modeling on the chemical composition of gas and dust in these systems are…
Motivated by the WMAP results indicating an early epoch of reionization, we consider alternative cosmic star formation models which are capable of reionizing the early intergalactic medium. We develop models which include an early burst of…
Understanding the collapse of clouds and the formation of protoplanetary disks is essential to understanding the formation of stars and planets. Infall and accretion, the mass-aggregation processes that occur at envelope and disk scales,…