Related papers: $^{13}$CO and $^{13}$CO$_2$ ice mixtures with N$_2…
The motivation to study experimentally CO ice under mimicked interstellar conditions is supported by the large CO gas abundances and ubiquitous presence of CO in icy grain mantles. Upon irradiation in its pure ice form, this highly stable…
Major components of ices on interstellar grains in molecular clouds - water and carbon oxides - occur at various optical depths. This implies that selective desorption mechanisms are at work. An astrochemical model of a contracting low-mass…
Interstellar ice mantles on the surfaces of dust grains are thought to have a bi-layered structure, with a H2O-rich polar layer, covered by a CO-rich apolar layer that probably harbors H2 and other volatiles such as N2. In this work, we…
Dust grains in cold circumstellar regions and dark-cloud interiors at 10-20 K are covered by ice mantles. A nonthermal desorption mechanism is invoked to explain the presence of gas-phase molecules in these environments, such as the…
Context. Interstellar ice is the main form of metal species in dark molecular clouds. Experiments and observations have shown that the ice is significantly processed after the freeze-out of molecules onto grains. The processing is caused by…
Context: HCOOH is one of the more common species in interstellar ices with abundances of 1-5% with respect to solid H2O. Aims: This study aims at characterizing the HCOOH spectral features in astrophysically relevant ice mixtures in order…
We present Temperature Programmed Desorption (TPD) experiments of CO and N2 ices in pure, layered and mixed morphologies at various ice "thicknesses" and abundance ratios as well as simultaneously taken Reflection Absorption Infrared…
Ice desorption affects the evolution of the gas-phase chemistry during the protostellar stage, and also determines the chemical composition of comets forming in circumstellar disks. From observations, most volatile species are found in…
Non-thermal desorption of inter- and circum-stellar ice mantles on dust grains, in particular ultraviolet photon-induced desorption, has gained importance in recent years. These processes may account for the observed gas phase abundances of…
Ultraviolet photodesorption of molecules from icy interstellar grains can explain observations of cold gas in regions where thermal desorption is negligible. This non-thermal desorption mechanism should be especially important where UV…
Current gas phase models do not account for the abundances of HNCO isomers detected in various environments, suggesting a formation in icy grain mantles. We attempted to study a formation channel of HNCO and its possible isomers by…
We present observations of the stretching mode of 13CO2 ice along 13 lines of sight in the Galaxy, using the Short Wavelength Spectrometer on board of the Infrared Space Observatory. Remarkable variations are seen in the absorption band…
Icy grain mantles are commonly observed through infrared spectroscopy toward dense clouds, cloud cores, protostellar envelopes and protoplanetary disks. Up to 80% of the available oxygen, carbon and nitrogen are found in such ices; the most…
Planet atmosphere and hydrosphere compositions are fundamentally set by accretion of volatiles, and therefore by the division of volatiles between gas and solids in planet-forming disks. For hyper-volatiles such as CO, this division is…
Solid O2 has been proposed as a possible reservoir for oxygen in dense clouds through freeze-out processes. The aim of this work is to characterize quantitatively the physical processes that are involved in the desorption kinetics of CO-O2…
Carbon dioxide is abundant in ice mantles of dust grains; some is found in the pure crystalline form as inferred from the double peak splitting of the bending profile at about 650 cm$^{-1}$. To study how CO$_2$ segregates into the pure form…
The structure and composition of simple ices can be modified during stellar evolution by protostellar heating. Key to understanding the involved processes are thermal and chemical tracers that can diagnose the history and environment of the…
The VUV absorption cross sections of most molecular solids present in interstellar ice mantles with the exception of H2O, NH3, and CO2 have not been reported yet. Models of ice photoprocessing depend on the VUV absorption cross section of…
Non-thermal desorption from icy grains containing H$_2$CO has been invoked to explain the observed H$_2$CO gas phase abundances in ProtoPlanetary Disks (PPDs) and Photon Dominated Regions (PDRs). Photodesorption is thought to play a key…
At the high densities and low temperatures found in star forming regions, all molecules other than H2 should stick on dust grains on timescales shorter than the cloud lifetimes. Yet these clouds are detected in the millimeter lines of…