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| Titel |
Stelllar wind induced soft X-ray emission from close-in exoplanets |
| VerfasserIn |
Kristina Kislyakova, Luca Fossati, Colin P. Johnstone, Mats Holmström, Valery V. Zaitsev, Helmut Lammer |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250122480
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| Publikation (Nr.) |
 EGU/EGU2016-1526.pdf |
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| Zusammenfassung |
| We estimate the X-ray emission from close-in exoplanets. We show that the Solar/Stellar
Wind Charge Exchange Mechanism (SWCX) which produces soft X-ray radiation is very
effective for hot Jupiters. In this mechanism, X-ray photons are produces by charge exchange
between heavy ions in the solar wind and the atmospheric neutral particles. This
mechanism is know to generate X-ray emission of comets in the Solar system. It has also
been shown to operate in the heliosphere, in the terrestrial magnetosheath, and
on Mars, Venus and Moon. Since the number of emitted photons is proportional
to the solar wind mass flux, this mechanism is not effective for the Solar system
giants. We present a simple estimate of the X-ray emission intensity that can be
produced by close-in extrasolar Hot Jupiters due to charge exchange with the heavy
ions of the stellar wind. Using the example of HD 209458b, we show that this
mechanism alone can be responsible for an X-ray emission of ≈ 1022 erg s−1,
which is 106 times stronger than the emission from the Jovian aurora. We discuss
the possibility to observe the predicted soft X-ray flux of hot Jupiters and show
that despite high emission intensities they are unobservable with current facilities. |
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