Search Publications
Recent results on the parameters of the interstellar helium from the ULYSSES/GAS experiment
Rosenbauer, H.; Witte, M.; Banaszkiewicz, M.
Velocity and direction of the flow of the interstellar helium and its temperature and density have been determined from the measurements of the ULYSSES/GAS experiment for two different epochs: during the in-ecliptic path of ULYSSES, representing solar maximum conditions, and during the south to the north pole transition (11/94-6/95), close to the …
Vlasov Theory of the Equilibrium Structure of Tangential Discontinuities in Space Plasmas
Roth, M.; de Keyser, J.; Kuznetsova, M. M.
Extensive theoretical work has been performed on the equilibrium structure of tangential discontinuities (TDs) in collisionless plasmas. This paper reviews kinetic models based on steady-state solutions of the Vlasov equation. It is shown that most of the existing models are special cases of a generalized multi-species model. In this generalized m…
The abundance of atomic 1H, 4He and 3He in the local interstellar cloud from pickup ion observations with SWICS on Ulysses
Gloeckler, George
Pickup ions measured deep inside the heliosphere open a new way to determine the absolute atomic density of a number of elements and isotopes in the local interstellar cloud (LIC). We derive the atomic abundance of hydrogen and the two isotopes of helium from the velocity and spatial distributions of interstellar pickup protons and ionized helium …
Relations Between ISM Inside and Outside the Heliosphere
Lallement, R.
Thanks to remarkable new tools, such as the Goddard High Resolution Spectrograph (GHRS) on board the HST and the EUVE spectrometer on the interstellar side, and Ulysses particle detectors on the heliospheric side, it is possible now to begin to compare abundances and physical properties of the interstellar matter outside the heliosphere (from abso…
In Situ Measurements of Interstellar Dust with the ULYSSES and Galileo Spaceprobes
Grün, Eberhard; Landgraf, Markus; Baguhl, Michael
Interstellar dust was first identified by the dust sensor onboard Ulysses after the Jupiter flyby in February 1992. These findings were confirmed by the Galileo experiment on its outbound orbit from Earth to Jupiter. Although modeling results show that interstellar dust is also present at the Earth orbit, a direct identification of interstellar gr…
Origin of C+ ions in the heliosphere
Geiss, J.; Gloeckler, G.; von Steiger, R.
C+ pickup ions were investigated with the SWICS instrument along the trajectory of Ulysses, covering a broad range of solar latitude and distance. Whereas nearly all the observed H+, He+, N+, O+ and Ne+ pickup ions are created from the interstellar gas penetrating deep into the heli…
The Interstellar Gas Flow Through the Heliospheric Interface Region
Fahr, Hans J.
The relative motion of the solar system with respect to the ambient interstellar medium forms a plasma interface region where the eventually subsonic, interstellar and solar wind plasma flows adapt to each other. In this region ahead of the solar system magnetohydrodynamically perturbed plasma flows are formed which, however, can be penetrated by …
The Acceleration of Pickup Ions
Giacalone, J.; Jokipii, J. R.
The well-established association of pickup ions with anomalous cosmic rays shows that acceleration of pickup ions to energies above 1 GeV occurs. At present, diffusive shock acceleration of the pickup ions at the termination shock of the solar wind seems to be the best candidate for acceleration to the high energies of anomalous cosmic rays, accou…
Modelling of the Interstellar Hydrogen Distribution in the Heliosphere
Bzowski, M.; Ruciński, D.
The detailed knowledge of the distribution of neutral interstellar hydrogen in the interplanetary space is necessary for a reliable interpretation of optical and H+ pickup ions observations. In the paper, we review the status of the modelling efforts with the emphasis on recent improvements in that field. We discuss in particular the ro…
GHRS Observations of the LISM
Linsky, Jeffrey L.
The GHRS has obtained high-resolution spectra of interstellar gas toward 19 nearby stars. These excellent data show that the Sun is located inside the Local Interstellar Cloud (LIC) with other warm clouds nearby. I will summarize the physical properties of these clouds and the three-dimensional structure of this warm interstellar gas. There is now…