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| Titel |
Energetic Neutral Hydrogen Atoms from the Heliosphere Measured with ASPERA-3 and ASPERA-4 |
| VerfasserIn |
André Galli, Peter Wurz, Peter Kollmann, Pontus C. Brandt, Maciej Bzowski, Justyna M. Sokól, Marzena A. Kubiak, Alexander Grigoriev, Stas Barabash |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250075339
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| Zusammenfassung |
| We re-analyze a residual signal of Energetic Neutral Atoms (ENAs) in the 0.4-5.0 keV range
across the sky obtained from the Neutral Particle Detector of the ASPERA-3&4 experiments
on board the Mars and Venus Express satellites. Due to improved knowledge of sensor
characteristics and exclusion of datasets affected by instrument effects, the typical intensity of
the ENA signal obtained by ASPERA-3 is an order of magnitude lower than in earlier reports.
The discrepancy between ASPERA-3 and ASPERA-4 no longer exists. We now also correct
the non-planetary signal for Compton-Getting and for ionization loss processes under the
assumption of a heliospheric origin of the ENAs. We find spectral shapes and intensities
(1Ã103 cm-2 sr-1 s-1) consistent with those measured by the Interstellar Boundary
Explorer (IBEX).
The principal advantage of ASPERA-3&4 with respect to the IBEX sensors is the higher
spectral resolution. In this presentation we discuss the physical significance of the spectral
shapes and their potential variation across the sky. At present, these observations are the only
independent confirmation of the heliospheric ENAs measured with IBEX in this energy
range. The ASPERA-3&4 measurements also allow to check for a temporal variation of the
heliospheric signal as they were obtained between 2003 and 2007, whereas IBEX is
operational since the end of 2008. |
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