相关论文: Extraterrestrial Photochemistry: Principles and Ap…
The interstellar medium is characterized by a rich and diverse chemistry. Many of its complex organic molecules are proposed to form through radical chemistry in icy grain mantles. Radicals form readily when interstellar ices (composed of…
Astrochemistry is a well-established multidisciplinary field devoted to study molecules in space. While most astrochemists are oriented to observe molecules in the gas phase and reproduce their abundances by modeling the physical conditions…
We demonstrate for the first time that Galactic cosmic rays with energies as high as 1e10 eV can trigger a cascade of low-energy (< 20 eV) secondary electrons that could be a significant contributor to the interstellar synthesis of…
Photochemistry has the potential to substantially impact the atmospheric composition of exoplanets with consequences on the radiative transfer, thermal structure and dynamics of the atmospheres, particularly in UV-rich stellar environments.…
In situ exploration of the planetary atmospheres requires the development of laboratory experiments to understand the molecular growth pathways initiated by photochemistry in the upper layers of the atmospheres. Major species and dominant…
The interaction of exoplanets with their host stars causes a vast diversity in bulk and atmospheric compositions, and physical and chemical conditions. Stellar radiation, especially at the shorter wavelengths, drives the chemistry in the…
Photoionization by high-energy photons creates nonthermal electrons with a broad range of energies that heat and chemically transform the atmospheres of planets. The specifics of the interactions are notably different when the gas is atomic…
In the past decade, there has been a significant shift in astrochemistry with a renewed focus on the role of non-thermal processes on the molecular interstellar medium, in particular energetic particles (such as cosmic ray particles and…
UV radiation can induce photochemical processes in exoplanet atmospheres and produce haze particles. Recent observations suggest that haze and/or cloud layers could be present in the upper atmospheres of exoplanets. Haze particles play an…
Given that the macromolecular building blocks of life were likely produced photochemically in the presence of ultraviolet (UV) light, we identify some general constraints on which stars produce sufficient UV for this photochemistry. We…
Charged dust grains in the atmospheres of exoplanets may play a key role in the formation of prebiotic molecules, necessary to the origin of life. Dust grains submerged in an atmospheric plasma become negatively charged and attract a flux…
Chemical kinetics plays an important role in controlling the atmospheric composition of all planetary atmospheres, including those of extrasolar planets. For the hottest exoplanets, the composition can closely follow…
{CircumStellar Envelopes (CSEs) of stars are complex chemical objects for which theoretical models encounter difficulties in elaborating a comprehensive overview of the occurring chemical processes. Along with photodissociation, ion-neutral…
Forty years ago it was proposed that gas phase organic chemistry in the interstellar medium was initiated by the methyl cation CH3+, but hitherto it has not been observed outside the Solar System. Alternative routes involving processes on…
Circumstellar disks are exposed to intense ultraviolet radiation from the young star. In the inner disks, the UV radiation can be enhanced by more than seven orders of magnitude compared with the average interstellar field, resulting in a…
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…
We present a comprehensive photochemistry model for exploration of the chemical composition of terrestrial exoplanet atmospheres. The photochemistry model is designed from the ground up to have the capacity to treat all types of terrestrial…
Molecules are ubiquitous in space. They are necessary component in the creation of habitable planetary systems and can provide the basic building blocks of life. Solid-state processes are pivotal in the formation of molecules in space and…
Photochemistry induced by stellar UV flux should produce haze particles in exoplanet atmospheres. Recent observations indicate that haze and/or cloud layers exist in the atmospheres of exoplanets. However, photochemical processes in…
In warm (equilibrium temperature <1000 K) gas giant exoplanet atmospheres, the observation of trace species in abundances deviating from thermochemical equilibrium predictions could be used as an indicator of disequilibrium chemical…