相关论文: Can Galactic chemical evolution explain the oxygen…
We discuss the connection between the chemistry of dense interstellar clouds and those characteristics of cometary matter that could be remnants of it. The chemical evolution observed to occur in molecular clouds is summarized and a model…
The early gas-dust solar nebula is considered: the gasdynamic theory is used to study the gravitational Jeans-type instability in its protoplanetary disk. The implications for the origin of the solar system are discussed. It is shown that a…
Understanding the phases of water ice that were present in the solar nebula has implications for understanding cometary and planetary compositions as well as internal evolution of these bodies. Here we show that amorphous ice formed more…
In this paper we study the very early phases of the evolution of our Galaxy by means of a chemical evolution model which reproduces most of the observational constraints in the solar vicinity and in the disk. We have restricted our analysis…
Interstellar dust is a significant component of matter in the galaxies. The dust owns its origin and reprocessing in a wide range of astrophysical environments. In order to understand the origin and evolution of the distinct types of…
The study of the chemical evolution of gas and dust from pre-stellar dense cores to circumstellar disks around young stars forms an essential part of understanding star- and planet formation. Throughout the collapse- and protostellar…
Using 17 chemical elements as a proxy for stellar DNA, we present a full phylogenetic study of stars in the solar neighbourhood. This entails applying a clustering technique that is widely used in molecular biology to construct an…
Despite a surface dominated by carbon-based life, the bulk composition of the Earth is dramatically carbon poor when compared to the material available at formation. Bulk carbon deficiency extends into the asteroid belt representing a…
The compositions of stars are a critical diagnostic tool for many topics in astronomy such as the evolution of our Galaxy, the formation of planets, and the uniqueness of the Sun. Previous spectroscopic measurements indicate a large…
The carbon to oxygen ratio in a protoplanetary disk can have a dramatic influence on the compositions of any terrestrial planets formed. In regions of high C/O, planets form primarily from carbonates and in regions of low C/O, the ratio of…
We compare the elemental depletions in the gas phase of the interstellar medium (ISM) with the elemental depletions in the rocky material of our Solar System. Our analysis finds a high degree of chemical complementarity: elements depleted…
The radioactive isotope $^{60}$Fe ($T_{1/2} = 1.5 $ Myr) was present in the early solar system. It is unlikely that it was injected directly into the nascent solar system by a single, nearby supernova. It is proposed instead that it was…
Models of the chemical evolution of our Galaxy are extended to include radial migration of stars and flow of gas through the disc. The models track the production of both iron and alpha elements. A model is chosen that provides an excellent…
Over the last two decades, the Sun has been observed to be depleted in refractory elements as a function of elemental condensation temperature (\tcond) relative to $\sim80\%$ of its counterparts. We assess the impact of Galactic chemical…
Gas-phase processes were long thought to be the key formation mechanisms for complex organic molecules in star-forming regions. However, recent experimental and theoretical evidence has cast doubt on the efficiency of such processes.…
Some low-density exoplanets are thought to be water-rich worlds that formed beyond the snow line of their protoplanetary disc, possibly accreting coequal portions of rock and water. However, the compositions of bodies within the Solar…
We numerically investigate abundance properties of the Galactic globular clusters (GCs) by adopting a new ``external pollution'' scenario. In this framework, GCs are assumed to originate in forming low-mass dwarfs embedded in dark matter…
The models that most successfully reproduce the orbital architecture of the Solar System terrestrial planets start from a narrow annulus of material that grows into embryos and then planets. However, it is not clear how this ring model can…
Galactic chemical evolution (GCE) is important for understanding the composition of the present-day interstellar medium (ISM) and of our solar system. In this paper, we aim to track the GCE by using the 29Si/30Si ratios in evolved stars and…
High temperature condensates found in meteorites display uranium isotopic variations (235U/238U) that complicate dating of the formation of the Solar System and whose origin remains mysterious. It is possible that these variations are due…