Search Publications
The new ESA meteoroid model
Dikarev, V.; Grün, E.; Landgraf, M. +3 more
The orbital distributions of meteoroids in interplanetary space are revised in the ESA meteoroid model to account for recently obtained observational data and to comply with the constraints due to the orbital evolution under planetary gravity and Poynting-Robertson effects. Infrared observations of the zodiacal cloud by the COBE DIRBE instrument, …
Irradiance models
Solanki, S. K.; Krivova, N. A.; Wenzler, T.
Measurements of solar irradiance have revealed variations at all the sampled time scales (ranging from minutes to the length of the solar cycle). One important task of models is to identify the causes of the observed (total and spectral) irradiance variations. Another major aim is to reconstruct irradiance over time scales longer than sampled by d…
Variation of the full Sun hydrogen Lyman profiles through solar cycle 23
Vial, J. -C.; Wilhelm, K.; Curdt, W. +3 more
The hydrogen Lyman (Lyα, 121.267 nm and Lyβ, 102.572 nm) lines are important contributors to the solar extreme ultra violet (EUV) flux which illuminates the upper Earth’s atmosphere. From high resolution spectral observations performed with the solar ultraviolet measurement of emitted radiations (SUMER) spectrometer on the Solar and Heliospheric O…
Titan atmosphere database
Lebonnois, S.; Rannou, P.; Luz, D. +1 more
We have developed in the last decade a two-dimensional version of the Titan global circulation model LMDZ. This model accounts for multiple coupling occuring on Titan between dynamics, haze, chemistry and radiative transfer. It was successful at explaining many observed features related to atmosphere state (wind, temperature), haze structure and c…
HST/ACS imaging of a Balmer-dominated shock in Kepler’s supernova remnant
Blair, William P.; Rudnick, Lawrence; Harrus, Ilana M. +3 more
Optical images of Kepler’s supernova remnant obtained at two epochs, in 1987 at Las Campanas Observatory and in 2003 with the HST Advanced Camera for Surveys, show the motion of the Balmer-dominated forward shock. The measured proper motion, combined with estimates of the shock velocity, is used to derive a distance of 3.9-0.9+1.4 kpc to the remna…
The influence of the solar particle and radiation environment on Titan’s atmosphere evolution
Lammer, H.; Penz, T.; Biernat, H. K. +1 more
Measurements of the 15N/ 14N isotope ratio in Titan's atmosphere by Earth-based millimetric wavelength spectroscopic observations of HC 15N/HC 14N indicate that the bulk nitrogen may be enriched in the heavy isotope 15N by about 3.9-4.5 times relative to the terrestrial value. For the explanat…
Gamma-ray observations of explosive nucleosynthesis products
Vink, Jacco
In this review I discuss the various γ-ray emission lines that can be expected and, in some cases have been observed, from radioactive explosive nucleosynthesis products. The most important γ-ray lines result from the decay chains of 56Ni, 57Ni, and 44Ti. 56Ni is the prime explosive nucleosynthesis produ…
The heliospheric modulation of 3 10 MeV electrons: Modeling of changes in the solar wind speed in relation to perpendicular polar diffusion
Fichtner, H.; Ferreira, S. E. S.; Potgieter, M. S. +3 more
The discrepancy between cosmic ray model predictions representing solar minimum conditions in the heliosphere and the 3-10 MeV post-1998 electrons observations by the Kiel Electron Telescope (KET) onboard Ulysses suggests the need for consistent changes in model parameters with increasing solar activity. In order to reduce this discrepancy, an eff…
Exploring the structure of galaxy clusters: XMM-Newton observations of the REFLEX-DXL clusters at z ∼ 0.3
Zhang, Y. -Y.; Finoguenov, A.; Böhringer, H. +5 more
The precise determination of global properties of galaxy clusters, and their scaling relations, is a task of prime importance for the use of clusters as cosmological probes. We performed a detailed XMM-Newton study of 14 X-ray luminous REFLEX Survey clusters at z ∼ 0.3. We found that the properties of the galaxy clusters show a self-similar behavi…
Cosmic-ray diffusion in the inner heliosphere
McKibben, R. B.
For about the last 40 years, we have been trying to understand the propagation of cosmic rays and other energetic charged particles through the interplanetary medium. Identification of the basic processes affecting the propagation, namely diffusion, convection by the solar wind, adiabatic deceleration, and gradient and curvature drifts, was attain…