相关论文: Neutral particle release from Europa's surface
We present a three-species multi-fluid MHD model (H$^+$, H$_2$O$^+$ and e$^-$), endowed with the requisite atmospheric chemistry, that is capable of accurately quantifying the magnitude of water ion losses from exoplanets. We apply this…
We present hemispherically resolved spectra of the surface of Europa from ~3.1--4.13 microns, which we obtained using the near infrared spectrometer NIRSPEC on the Keck II telescope. These include the first high-quality L-band spectra of…
The dissociative ionization of H2+ interacting with intense, femtosecond extreme-ultraviolet laser pulses is investigated theoretically. This is done by numerical propagation of the time-dependent Schr\"{o}dinger equation for a colinear…
A survey of mid-IR gas-phase emission lines of H2, H2O and various atoms toward a sample of 43 embedded low-mass young stars in nearby star-forming regions is presented. The sources are selected from the Spitzer "Cores to Disks" (c2d)…
A new method involving mass spectrometry and modelling is described in this work, which may highlight the production mechanisms of negative ions on surface in low pressure plasmas. Positive hydrogen ions from plasma impact a sample which is…
In the interstellar medium (ISM), the formation of complex organic molecules (COMs) is largely facilitated by surface reactions. However, in cold dark clouds, thermal desorption of COMs is inefficient because of the lack of thermal energy…
UV irradiation of simple ices is proposed to efficiently produce complex organic species during star- and planet-formation. Through a series of laboratory experiments, we investigate the effects of the H2O concentration, the dominant ice…
Close-in hot Jupiters are exposed to a tremendous photon flux that ionizes the neutral escaping material from the planet leaving an observable imprint that makes them an interesting laboratory for testing theoretical models. In this work we…
The evaporation and the chemistry of the atmospheres of warm and hot planets are strongly determined by the high-energy irradiation they receive from their parent stars. This is more crucial among young extra-solar systems, due to the high…
The bolometric radiation from a central body is potentially a powerful driver of atmospheric escape from planets or satellites. When heated above their equilibrium temperatures those satellites, due to their low surface gravity, are be…
We investigate the dependence of the yield of positive secondary ions created upon impact of primary He, B and Ne ions on geometry and electronic and nuclear energy deposition by the projectiles. We employ pulsed beams in the medium energy…
The distribution of ions at the air/water interface plays a decisive role in many natural processes. It is generally understood that polarizable ions with low charge density are surface-active, implying they sit on top of the water surface.…
Intense X-ray and ultraviolet stellar irradiation can heat and inflate the atmospheres of closely orbiting exoplanets, driving mass outflows that may be significant enough to evaporate a sizable fraction of the planet atmosphere over the…
Using a helium ion hitting various metal surfaces as a model system, we describe a general quantum-kinetic approach for calculating ion-induced secondary electron emission spectra at impact energies where the emission is driven by the…
The ultraviolet (UV) photodissociation of amorphous water ice at different ice temperatures is investigated using molecular dynamics (MD) simulations and analytical potentials. Previous MD calculations of UV photodissociation of amorphous…
The Galilean moons exhibit a decrease in bulk density with distance from Jupiter, which may reflect differences in evolutionary paths and water loss. Early in its history, Jupiter was more luminous and may have driven substantial…
The classical theory of ion beam sputtering predicts the instability of a flat surface to uniform ion irradiation at any incidence angle. We relax the assumption of the classical theory that the average surface erosion rate is determined by…
Thermal measurements constrain the physical properties of icy satellite surfaces, including grain size, porosity, and regolith structure. On Europa, analyses of the Galileo Photopolarimeter-Radiometer (PPR) dataset revealed thermal inertia…
We explore ion escape from, and solar ion deposition to, \hll{an unmagnetized Earth-like planet}. We use RHybrid, an ion-kinetic electron-fluid code to simulate the global plasma interaction of unmagnetized Earth with the solar wind. We…
The European Spallation Source (ESS), presently well on its way to completion, will soon provide the most intense neutron beams for multi-disciplinary science. Fortuitously, it will also generate the largest pulsed neutrino flux suitable…