Related papers: Laboratory H2O:CO2 ice desorption data: entrapment…
CO2 is one of the dominant components of the interstellar ice. Recent observations show CO2 exists more abundantly in polar (H2O-dominated) ice than in apolar (H2O-poor) ice. CO2 ice formation is primarily attributed to the reaction between…
CO$_2$ ice is an important reservoir of carbon and oxygen in star and planet forming regions. Together with water and CO, CO$_2$ sets the physical and chemical characteristics of interstellar icy grain mantles, including desorption and…
Ice mantles play a crucial role in shaping the astrochemical inventory of molecules during star and planet formation. Small-scale molecular processes have a profound impact on large-scale astronomical evolution. The areas of solid-state…
Ices regulate much of the chemistry during star formation and account for up to 80% of the available oxygen and carbon. In this paper, we use the Spitzer c2d ice survey, complimented with data sets on ices in cloud cores and high-mass…
During the evolution of diffuse clouds to molecular clouds, gas-phase molecules freeze out on surfaces of small dust particles to form ices. On dust surfaces, water is the main constituent of the icy mantle in which a complex chemistry is…
Acetic acid (CH3COOH) was detected in the gas toward interstellar clouds, hot cores, protostars and comets. Its formation in ice mantles was proposed and acetic acid awaits detection in the infrared spectra of the ice as most other COMs…
Solid-phase photo-processes involving icy dust grains greatly affect the chemical evolution of the interstellar medium by leading to the formation of complex organic molecules and by inducing photodesorption. So far, the focus of laboratory…
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…
Spectroscopic studies play a key role in the identification and analysis of interstellar ices and their structure. Some molecules have been identified within the interstellar ices either as pure, mixed, or even as layered structures.…
Diffusion of atoms and molecules is a key process for the chemical evolution in the star forming regions of the interstellar medium. Accurate data on the mobility of many important interstellar species is however often not available and…
Aims. In this paper we investigate the detectability of the molecular oxygen in icy dust grain mantles towards astronomical objects. Methods. We present a systematic set of experiments with O2-H2O ice mixtures designed to disentangle how…
Dissociation of gas hydrates below 240 K leads to the formation of a metastable form of water ice, so called cubic ice (Ic). Through its defective nature and small particle size the surface film composed of such material is incapable of…
(Abridged*) Models of the young solar nebula assume a hot initial disk with most volatiles are in the gas phase. The question remains whether an actively accreting disk is warm enough to have gas-phase water up to 50 AU radius. No detailed…
Ices are an important constituent of protoplanetary disks. New observational facilities, notably the James Webb Space Telescope (JWST), will greatly enhance our view of disk ices by measuring their infrared spectral features. We present a…
This paper presents Spitzer-IRS spectroscopy of the CO2 15.2 micron bending mode toward a sample of 50 embedded low-mass stars in nearby star-forming clouds, taken mostly from the ``Cores to Disks (c2d)'' Legacy program. The average…
We study the chemical evolution of H2O:CO:NH3 ice mixtures irradiated with soft X-rays, in the range 250-1250 eV. We identify many nitrogen-bearing molecules such as e.g., OCN-, NH4+ , HNCO, CH3CN, HCONH2, and NH2COCONH2. Several infrared…
We suggest that three-body chemistry may occur in warm high density gas evaporating in transient co\textendash desorption events on interstellar ices. Using a highly idealised computational model we explore the chemical conversion from…
We demonstrate the measurement and manipulation of the temperature of cold CO molecules in a microchip environment. Through the use of time-resolved spatial imaging, we are able to observe the phase-space distribution of the molecules, and…
We present a chemical kinetics model of the solid-phase chemical evolution of a comet, beginning with a long period of cold-storage in the Oort Cloud, followed by five orbits that bring the comet close to the Sun. The chemical model is…
We investigate the chemical evolution of a forming molecular cloud behind an interstellar shock wave. We conduct three-dimensional magnetohydrodynamics simulations of the converging flow of atomic gas, including a simple chemical network…