Europa's oxygen atmosphere

Stability of an Oxygen Atmosphere on Ganymede

Photolysis of water and subsequent escape of hydrogen can give rise to an oxygen atmosphere on Ganymede. Growth of the atmosphere may be limited by escape of fast oxygen atoms formed by photodissociation of 02. Escape of oxygen and hydrogen in an equilibrium configuration should balance net evaporation of water from the satellite's surface and the partial pressure of atmospheric O2 could be as ...

Detailed Atmosphere Modelling for the Neutron Star 1e1207.4-5209: Evidence of Oxygen/neon Atmosphere

We present a comprehensive investigation of the two broad absorption features observed in the X-ray spectrum of the neutron star 1E1207.4-5209 based on a recent analysis of the 260 ksec XMM-Newton data by Mori et al. 2005. Expanding on our earlier work (Hailey & Mori 2002) we have examined all previously proposed atmospheric models for 1E1207.4-5209. Using our atomic code, which rapidly solves ...

From the Atmosphere to the Mitochondrion: The Oxygen Cascade

Oxygen is essential for energy metabolism whereby the energy trapped in chemical bonds in food stuffs is transferred in a series of stepwise chemical reactions to be available for all cellular functions in the form of high-energy phosphate compounds (adenosine triphosphate and creatine phosphate). Whereas there are energy-generating processes that do not require oxygen, their contribution to th...

Energetic oxygen in the upper atmosphere and the laboratory.

Detection of oxygen traces in nitrogen and hydrogen-rich atmosphere

Tin oxide sensors are evaluated to detect traces of oxygen in the range 0–100 ppm both in nitrogen and hydrogen (4.5 vol% H2 in N2) atmospheres. In nitrogen, significant relative responses to oxygen are measured at 623 K and 723 K. However, at lower temperature, 523 K, the response strongly decreases. In the presence of hydrogen, on the contrary, interesting responses are measured at 523 K. At ...