Related papers: Clouds, Clumps, Cores & Comets - a Cosmic Chemical…
The study of protostellar collapse or infall has proven unusually difficult and controversial. Some historical context will be provided, against which recent advances can be measured. We now have a substantial number of objects with…
The development of our understanding of the gaseous component of the interstellar medium is reviewed. During the 20th century our picture of diffuse material in space has grown from a simple model of isolated clouds in thermal equilibrium…
The isothermal dynamical evolution of a clumpy and turbulent molecular cloud region and its fragmentation into a protostellar cluster is investigated numerically. The effect of different initial density and velocity distributions, generated…
Improving our understanding of the earliest stages of star formation is crucial to gain insight into the origin of stellar masses, multiple systems, and protoplanetary disks. We discuss recent advances made in this area thanks to detailed…
Molecular clouds are the principle stellar nurseries of our universe, keeping them in the focus of both observational and theoretical studies. From observations, some of the key properties of molecular clouds are well known but many…
Since very recently, we acquired knowledge on the existence of comets in extrasolar planetary systems. The formation of comets together with planets around host stars now seems evident. As stars are often born in clusters of interstellar…
Context. The abundances of many observed compounds in interstellar molecular clouds still lack an explanation, despite extensive research that includes both gas and solid (dust-grain surface) phase reactions. Aims. We aim to qualitatively…
We discuss models that astrochemists have developed to study the chemical composition of the interstellar medium. These models aim at computing the evolution of the chemical composition of a mixture of gas and dust under as- trophysical…
The isothermal gravitational collapse and fragmentation of a region within a molecular cloud and the subsequent formation of a protostellar cluster is investigated numerically. The clump mass spectrum which forms during the fragmentation…
The review contains an analysis of the observed and model curves of the interstellar extinction and polarization. The observations mainly give information on dust in diffuse and translucent interstellar clouds. The features of various dust…
We formulate the problem of the formation and collapse of nonaxisymmetric protostellar cores in weakly ionized, self-gravitating, magnetic molecular clouds. In our formulation, molecular clouds are approximated as isothermal, thin (but with…
The network of interactions between hot gas, cool clouds, massive stars, and stellar remnants used in the chemodynamical modeling of the interstellar medium is investigated for the types of its solutions. In a physically consistent…
Chemical evolution of galaxies brings together ideas on stellar evolution and nucleosynthesis with theories of galaxy formation, star formation and galaxy evolution, with all their associated uncertainties. In a new perspective brought…
In this chapter we review the astrophysical origins of Earth's carbon, starting from the products of the Big Bang and culminating with the Earth's formation. We review the measured compositions of different primitive objects including…
We present preliminary results on the effects of mergers on the chemical properties of galactic objects in hierarchical clustering scenarios. We adopt a hydrodynamical chemical code that allows to describe the coupled evolution of dark…
(English) In this lecture I discuss recent progress in the understanding of the chemical evolution of protoplanetary disks that resemble our Solar system during the first ten million years. At the verge of planet formation, strong…
In this chapter, we explore the origins of cometary material and discuss the clues cometary composition provides in the context of the origin of our solar system. The review focuses on both cometary refractory and volatile materials, which…
We discuss the lifetimes and evolution of dense cores formed as turbulent density fluctuations in magnetized, isothermal molecular clouds. We consider numerical simulations in which we measure the cores' magnetic criticality and Jeans…
Carbon is an essential element for a habitable world. Inner (r < 3 au) disk planetary carbon compositions are strongly influenced by supply and survival of carbonaceous solids. Here we trace the journey of carbon from the interstellar…
The physical conditions in a collapsing cloud can be traced by observations of molecular lines. To correctly interpret these observations the abundance distributions of the observed species need to be derived. The chemistry in a collapsing…