Astrochemistry of dust, ice and gas: introduction and overview

Abstract

A brief introduction and overview of the astrochemistry of dust, ice and gas and their interplay is presented, aimed at non-specialists. The importance of basic chemical physics studies of critical reactions is illustrated through a number of recent examples. Such studies have also triggered new insight into chemistry, illustrating how astronomy and chemistry can enhance each other. Much of the chemistry in star- and planet-forming regions is now thought to be driven by gas-grain chemistry rather than pure gas-phase chemistry, and a critical discussion of the state of such models is given. Recent developments in studies of diffuse clouds and PDRs, cold dense clouds, hot cores, protoplanetary disks and exoplanetary atmospheres are summarized, both for simple and more complex molecules, with links to papers presented in this volume. In spite of many lingering uncertainties, the future of astrochemistry is bright: new observational facilities promise major advances in our understanding of the journey of gas, ice and dust from clouds to planets.Comment: Introductory paper for Faraday Discussions 168 conference, April 201

Methane ice photochemistry and kinetic study using laser desorption time-of-flight mass spectrometry at 20 K

“…1 The reliability of these models depends on the accuracy of the reaction rate coefficients that are contained in databases for use in astrochemistry (e.g., UMIST Database for Astrochemistry, 2 NIST Chemical Kinetics Database, 3 KInetic Database for Astrochemistry 4 ). Models of interstellar chemistry involving both gas-phase and solid-phase reactions are employed to understand the complex chemical formation routes of the observed species and to predict their abundances in the regions where they reside.…”

Non-thermal ion desorption from an acetonitrile (CH3CN) astrophysical ice analogue studied by electron stimulated ion desorption

“…Inside dense molecular clouds, most molecules are expected to directly freeze out onto the surface of cold dust grains, 14 forming ice mantles. Nonetheless, there is also the possibility of in situ formation of CH 3 CN by the radiative association reaction CH 3 + CN -CH 3 CN, and by hydrogenation of C 2 N on grains at earlier times of star-formation.…”

Chemie mit Überschall: 30 Jahre astrochemische Forschung und künftige Herausforderungen

“…Der Staub im Universum spielt eine bedeutende Rolle bei dessen Entstehen. Staubkörner beeinflussen die Chemie der Gasphase und die Dynamik der Sternbildung, sind Vorstufen von Planeten und Kometen und Überreste von protoplanetaren Scheiben . Ein Überbegriff für “subplanetare” Feststoffe ist “Trümmerscheibe”.…”

“…Hauptkomponente des interstellaren Staubs sind kohlenstoffhaltige Materialien, die in vielen interstellaren Prozessen eine Schlüsselrolle spielen . Ein weiteres wichtiges Material sind amorphe Silikate, während andere Arten von Feststoffen, wie etwa Eisenoxide, Carbide, Sulfide oder metallisches Eisen Nebenbestandteile darstellen .…”