Related papers: Heavy ion irradiation of crystalline water ice
Desorption of H2O films ranging from 53 nanometres to 101 micrometre thicknesses have been investigated using a quartz-crystal microbalance (QCM) and temperature-programmed desorption. Three desorption stages are observed belonging to…
Cool objects glow in the infrared. The gas and solid-state species that escape the stellar gravitational attraction of evolved late-type stars in the form of a stellar wind are cool, with temperatures typically $\la$1500\,K, and can be…
Context: Broadband optical constants of astrophysical ice analogues in the infrared (IR) and terahertz (THz) ranges are required for modeling the dust continuum emission and radiative transfer in dense and cold regions, where thick icy…
We investigate ice polyamorphism in the context of the two-dimensional Mercedes-Benz model of water. We find a first-order phase transition between a crystalline phase and a high-density amorphous phase. Furthermore we find a reversible…
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…
The aim of this study is to understand the chemical conditions of ices around embedded young stellar objects (YSOs) in the metal-poor Large Magellanic Cloud (LMC). We performed near-infrared (2.5-5 micron) spectroscopic observations toward…
Ultraviolet irradiation of ice is of great interest for understanding the chemistry in both atmospheric and astrophysical environments. In interstellar space, photodissociation of H2O molecules can be a driving force behind the chemistry on…
Near-infrared surveys of high-mass star-forming regions start to shed light onto their stellar content. A particular class of objects found in these regions, the so-called massive Young Stellar Objects (YSOs) are surrounded by dense…
K-shell ionization and characteristic x-ray radiation (CXR) by high-energy electrons and positrons in oriented silicon crystals are studied using computer simulation. A method for this simulation has been developed and is described in…
Sensitive 5-38 um Spitzer Space Telescope (SST) and ground based 3-5 um spectra of the embedded low mass protostars B5 IRS1 and HH46 IRS show deep ice absorption bands superposed on steeply rising mid-infrared continua. The ices likely…
The bulk propagation speed of GeV-energy cosmic rays is limited by frequent scattering off hydromagnetic waves. Most galaxy evolution simulations that account for this confinement assume the gas is fully ionized and cosmic rays are…
We investigate the solidification of a water rivulet flowing over a cold inclined substrate and the resulting formation of three-dimensional ice structures. Using a controlled hydraulic and thermal setup, combined with spatiotemporal…
Observations of H3+ in the Galactic diffuse interstellar medium (ISM) have led to various surprising results, including the conclusion that the cosmic-ray ionization rate (zeta_2) is about 1 order of magnitude larger than previously…
Despite the ubiquity of ice, a molecular-resolution image of ice crystallized from liquid water or the resulting defect structure has never been obtained. Here, we report the stabilization and angstrom-resolution electron imaging of ice Ih…
We present the first three-dimensional radiation-magnetohydrodynamic simulations of the photoionisation of a dense, magnetised molecular globule by an external source of ultraviolet radiation. We find that, for the case of a strong ionising…
Freezing in the vicinity of water-vapor interfaces is of considerable interest to a wide range of disciplines, most notably the atmospheric sciences. In this work, we use molecular dynamics and two advanced sampling techniques, forward flux…
The structural dynamics of ice in the freezing - thawing process has been studied in the context of the concept of two-phase water. It was previously shown that water is a two-phase system consisting of free and bound (liquid crystal)…
Gas hydrates grown at gas-ice interfaces are examined by electron microscopy and found to have a submicron porous texture. Permeability of the intervening hydrate layers provides the connection between the two counterparts (gas and water…
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 performed small-angle X-ray scattering measurements of liquid Te using a synchrotron radiation facility and observed the maximum scattering intensity near 620 K in the supercooled region (melting temperature 723 K). This result is an…