Related papers: Interstellar Hydrides
Formed at an early stage of gas-phase ion-molecule chemistry, hydrides -- molecules containing a heavy element covalently bonded to one or more hydrogen atoms -- play an important role in interstellar chemistry as they are the progenitors…
The field of astrochemistry has seen major advances triggered by the completion of new powerful radio telescopes, with gains in sensitivity of receivers and in bandwidth. To date, about 330 molecular species are detected, in interstellar…
Water is observed throughout the universe, from diffuse interstellar clouds to protoplanetary disks around young stars, and from comets in our own solar system and exoplanetary atmospheres to galaxies at high redshifts. This review…
Molecular hydrogen has an important role in the early stages of star formation as well as in the production of many other molecules that have been detected in the interstellar medium. In this review we show that it is now possible to study…
In the currently-accepted model for star formation out of the interstellar gas in galaxies, the basic construction material is assumed to be large clouds of atomic hydrogen (HI). These clouds are thought to form higher-density complexes of…
Hydrides are key ingredients of interstellar chemistry since they are the initial products of chemical networks that lead to the formation of more complex molecules. The fundamental rotational transitions of light hydrides fall into the…
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…
A broad array of interstellar absorption features that appear in the ultraviolet spectra of bright sources allows us to measure the abundances and ionization states of many important heavy elements that exist as free atoms in the…
This review covers four current questions in the behavior of the atomic and molecular interstellar medium. These include whether the atomic gas originates primarily in cold streams or hot flows onto galaxies; what the filling factor of cold…
Context: Hydrides of the most abundant heavier elements are fundamental molecules in cosmic chemistry. Some of them trace gas irradiated by UV or X-rays. Aims: We explore the abundances of major hydrides in W3 IRS5, a prototypical region of…
Recent studies of the nearest star-forming clouds of the Galaxy at submillimeter wavelengths with the Herschel Space Observatory have provided us with unprecedented images of the initial conditions and early phases of the star formation…
The presence of H3+ in the interstellar medium was forecast almost four decades ago. Almost three decades ago it was asserted that its reactions with neutral molecular and atomic species directly lead to the production of many of the…
The interstellar medium (ISM) is a key ingredient in galaxy formation and evolution as it provides the molecular gas reservoir which fuels star formation and supermassive black hole accretion. Yet the ISM is one of the least studied aspects…
The past century of interstellar dust has brought us from first ignoring it to finding that it is an important component of the interstellar medium and plays an important role in the evolution of galaxies, the formation of stars and…
Molecular hydrogen (H2) is the primary component of the reservoirs of cold, dense gas that fuel star formation in our galaxy. While the H2 abundance is ultimately regulated by physical processes operating on small scales in the interstellar…
As building blocks of dust, rocky planets, and even complex life, the chemical elements heavier than hydrogen (H) and helium (He) - called "metals" in astronomy - play an essential role in our Universe and its evolution. Up to Fe and Ni,…
The majority of hydrogen in the interstellar medium (ISM) is in atomic form. The transition from atoms to molecules and, in particular, the formation of the H$_2$ molecule, is a key step in cosmic structure formation en route to stars.…
The main achievements, current developments and prospects of molecular studies in external galaxies are reviewed. They are put in the context of the results of several decades of studies of molecules in local interstellar medium, their…
Lyman and Werner band absorption features from interstellar molecular hydrogen in rotational levels J = 0, 1, 2, 3 and 5 were observed in the spectrum of zeta Ori A by the Interstellar Medium Absorption Profile Spectrograph (IMAPS). Most of…
Astrochemistry is a well-established multidisciplinary field devoted to study molecules in space. While most astrochemists are oriented to observe molecules in the gas phase and reproduce their abundances by modeling the physical conditions…