相关论文: Is acetylene essential for carbon dust formation?
Molecular hydrogen is the most abundant molecule in the universe. It is the first one to form and survive photo-dissociation in tenuous environments. Its formation involves catalytic reactions on the surface of interstellar grains. The…
We investigate the time evolution of dust properties, molecular hydrogen (H_2) contents, and star formation histories in galaxies by using our original chemodynamical simulations. The simulations include the formation of dust in the stellar…
We present self-consistent dynamical models for dust-driven winds of carbon-rich AGB stars. The models are based on the coupled system of frequency-dependent radiation hydrodynamics and time-dependent dust formation. We investigate in…
Stars form within dense cores composed of both gas and dust within molecular clouds. However, despite the crucial role that dust plays in the star formation process, its dynamics is frequently overlooked, with the common assumption being a…
Although dust is widely found in astrophysics, forming dust is surprisingly difficult. The proper combination of low temperature (<2000 K) and high density is mainly found in the winds of late-type giant and supergiant stars which, as a…
Context. Cosmic dust is ubiquitous in astrophysical environments, where it significantly influences the chemistry and the spectra. Dust grains are likely to grow through the accretion of atoms and molecules from the gas-phase onto them.…
An overview is given of the chemical processes that occur in primordial systems under the influence of radiation, metal abundances and dust surface reactions. It is found that radiative feedback effects differ for UV and X-ray photons at…
We review the observational evidence for dust formation in Wolf-Rayet binary systems and in Type II Supernova ejecta. Existing theoretical models describing the condensation of solids in carbon-rich Wolf-Rayet stars and in Supernovae close…
Protoplanetary discs are dynamic environments where the interplay between chemical processes and mass transport shapes the composition of gas and dust available for planet formation. We investigate the combined effects of volatile chemistry…
Ubiquitously found in the Universe, atomic hydrogen represents up to 70% of the neutral gas composition of the Milky Way. As an adatom, hydrogen can physisorb or chemisorb onto interstellar dust grains and icy mantles, thereby contributing…
We investigate the role of dust in star formation activity of extremely metal-poor blue compact dwarf galaxies (BCDs). Observations suggest that star formation in BCDs occurs in two different regimes: "active" and "passive". The "active"…
Condensation of circumstellar dust begins with formation of molecular clusters close to the stellar photosphere. These clusters are predicted to act as condensation cores at lower temperatures and allow efficient dust formation farther away…
Polycyclic aromatic hydrocarbons (PAHs) and fullerenes play a major role in the physics and chemistry of the interstellar medium. Based on a number of recent experimental and theoretical investigations we developed a model in which PAHs are…
The early stages of star formation are closely related to the ambient conditions in the interstellar medium. Important questions such as dust abundance, size distribution, temperature distribution, fraction of molecular gas, fraction of…
We investigate the sources and amount of dust in early galaxies. We discuss dust nucleation in stellar atmospheres using published extended atmosphere models, stellar evolution tracks and nucleation conditions and conclude that the (TPAGB)…
Aims: To calculate chemistry and gas temperature of evolving protoplanetary disks with decreasing mass or dust settling, and to explore the sensitivity of gas-phase tracers. Methods: The density and dust temperature profiles for a range of…
Context. The evolution of amorphous hydrocarbon materials, a-C(:H), principally resulting from ultraviolet (UV) photon absorption- induced processing, are likely at the heart of the variations in the observed properties of dust in the…
In order to find out capable molecular source of astronomically well observed infrared (IR) spectrum, asymmetric molecular configuration polycyclic aromatic hydrocarbon (PAH) was analyzed by the density functional theory (DFT) analysis.…
Because H2 formation on dust grain surfaces completely dominates gas-phase H2 formation in local molecular clouds, it is often assumed that gas-phase formation is never important. In fact, it is the dominant mechanism in a number of cases.…
Astrochemical surface reactions are thought to be responsible for the formation of complex organic molecules, which are of potential importance for the origin of life. In a situation, when the chemical composition of dust surfaces is not…