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RESEARCH PRODUCT
Stellar X-ray heating of planet atmospheres
Giuseppina MicelaCesare Cecchi-pestelliniAngela Ciaravellasubject
PhysicsAstrophysics::High Energy Astrophysical PhenomenaCompton scatteringAstronomy and AstrophysicsElectronAstrophysicsPhotoionizationPlanetary systemLuminositySpace and Planetary SciencePlanetRadiative transferAstrophysics::Solar and Stellar AstrophysicsDeposition (phase transition)Astrophysics::Earth and Planetary AstrophysicsAstrophysics::Galaxy Astrophysicsdescription
Aims. To investigate the effects of the stellar X-ray irradiation on planet atmospheres, we study the X-ray transfer and energy deposition in a hydrogen rich gas. Methods. We construct an accurate X-ray transfer model taking both photoionization and Compton scattering into account; the electron energy deposition is followed by tracking the discrete exchange processes between electrons and the gas mixture. Results. Exospheric heating rates are derived as functions of the pressure in model atmospheres using a wide range of X-ray luminosity, spectral hardness representative of different stellar ages, and distances from the parent star. The computed heating rates suggest that X-ray irradiation might be an important heating source in planetary exospheres even at large distances from the parent star.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2006-09-13 | Astronomy & Astrophysics |