Related papers: Clouds, Clumps, Cores & Comets - a Cosmic Chemical…
An outstanding question of astrobiology is the link between the chemical composition of planets, comets, and other solar system bodies and the molecules formed in the interstellar medium. Understanding the chemical and physical evolution of…
Within the framework of The Heterogeneous dust Evolution Model at the IaS (THEMIS) this work investigates in detail the surface processes and chemistry relating to core/mantle interstellar and cometary grain structures and its influence on…
Context: The chemical composition of a molecular cloud changes dramatically as it collapses to form a low-mass protostar and circumstellar disk. Two-dimensional (2D) chemodynamical models are required to properly study this process. Aims:…
(Abridged) Aims & Methods. A two-dimensional, semi-analytical model is presented that follows, for the first time, the chemical evolution from a collapsing molecular cloud (a pre-stellar core) to a protostar and circumstellar disk. The…
We review recent studies of organic molecule formation in dense molecular clouds and in comets. We summarise the known organic inventories of molecular clouds and recent comets, particularly Hale-Bopp. The principal chemical formation…
In this paper, we review some of the properties of dense molecular cloud cores. The results presented here rely on three-dimensional numerical simulations of isothermal, magnetized, turbulent, and self-gravitating molecular clouds (MCs) in…
We have extensively mapped a sample of dense molecular clouds (L1512, TMC-1C, L1262, Per 7, L1389, L1251E) in lines of HC3N, CH3OH, SO and C^{18}O. We demonstrate that a high degree of chemical differentiation is present in all of the…
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…
Stars form within molecular clouds but our understanding of this fundamental process remains hampered by the complexity of the physics that drives their evolution. We review our observational and theoretical knowledge of molecular clouds…
The thermal and chemical evolution of gravitationally collapsing protostellar clouds is investigated, focusing attention on their dependence on metallicity. Calculations are carried out for a range of metallicities spanning the local…
Complex organic molecules (COMs) are widely detected in protostellar and protoplanetary systems, where they are thought to have been inherited in large part from earlier evolutionary phases. The chemistry of COMs in these earlier phases,…
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…
We discuss new developments of interstellar chemistry, with particular emphasis on the carbon chemistry. We confirm that carbon chains and cycles are ubiquitous in the ISM and closely chemically related to ea ch other, and to carbon.…
We develop a statistical approach for description of dense structures (cores) in molecular clouds that might be progenitors of stars. Our basic assumptions are a core mass-density relationship and a power-law density distribution of these…
We construct models of molecular clouds that are considered as ensembles of transient cores. Each core is assumed to develop in the background gas of the cloud, grow to high density and decay into the background. The chemistry in each core…
To study the chemical evolution during the formation of molecular clouds, we model three types of clouds with different density structures: collapsing spherical, collapsing ellipsoidal, and static spherical profiles. The collapsing models…
The dense molecular cloud cores that form stars, like other self-gravitating objects, undergo bulk oscillations. Just at the point of gravitational instability, their fundamental oscillation mode has zero frequency. We study, using…
I review some steps in the conversion of molecular cloud gas into stars and planets, with an emphasis in this presentation on the early stage molecular cloud fragmentation that leads to elongated filaments/ribbons. Magnetic fields can play…
We review the progress made in understanding molecular cloud formation and evolution toward star formation since the first Crete conference in 1990. It now seems clear that molecular clouds in the Galaxy at least form from compressed HI…
This paper reviews the chemistry of star-forming regions, with an emphasis on the formation of high-mass stars. We first outline the basic molecular processes in dense clouds, their implementation in chemical models, and techniques to…