Search Publications
EISCAT and Cluster observations in the vicinity of the dynamical polar cap boundary
Dandouras, I.; Amm, O.; Fazakerley, A. +5 more
The dynamics of the polar cap boundary and auroral oval in the nightside ionosphere are studied during late expansion and recovery of a substorm from the region between Tromsø (66.6° cgmLat) and Longyearbyen (75.2° cgmLat) on 27 February 2004 by using the coordinated EISCAT incoherent scatter radar, MIRACLE magnetometer and Cluster satellite measu…
Drift-Alfvén vortices at the ion Larmor radius scale
Krasnoselskikh, V. V.; Pokhotelov, O. A.; Onishchenko, O. G.
The theory of nonlinear drift-Alfvén waves with the spatial scales comparable to the ion Larmor radius is developed. It is shown that the set of equations describing the nonlinear dynamics of drift-Alfvén waves in a quasistationary regime admits a solution in the form of a solitary dipole vortex. The vortex structures propagating perpendicular to …
XMM-Newton Observations of the Nuclei of the Radio Galaxies 3C 305, DA 240, and 4C 73.08
Lee, Julia C.; Kraft, Ralph P.; Birkinshaw, Mark +4 more
We present new XMM-Newton EPIC observations of the nuclei of the nearby radio galaxies 3C 305, DA 240, and 4C 73.08, and investigate the origin of their nuclear X-ray emission. The nuclei of the three sources appear to have different relative contributions of accretion- and jet-related X-ray emission, as expected based on earlier work. The X-ray s…
On the rotational dynamics of Prometheus and Pandora
Melnikov, A. V.; Shevchenko, I. I.
Possible rotation states of two satellites of Saturn, Prometheus (S16) and Pandora (S17), are studied by means of numerical experiments. The attitude stability of all possible modes of synchronous rotation and the motion close to these modes is analyzed by means of computation of the Lyapunov spectra of the motion. The stability analysis confirms …
Modeling magnetohydrodynamics and non-equilibrium SoHO/UVCS line emission of CME shocks
Raymond, J. C.; Orlando, S.; Reale, F. +1 more
Aims: We provide a guideline to interpret the UltraViolet Coronograph Spectrometer (UVCS) emission lines (in particular O VI and Si XII) during shock wave propagation in the outer solar corona.
Methods: We use a numerical magnetohydrodynamic (MHD) model performing a set of simulations of shock waves generated in the corona and from the result …
Detecting transits from Earth-sized planets around Sun-like stars
Fridlund, M.; Carpano, S.
Context: Detecting regular dips in the light curve of a star is an easy way to detect the presence of an orbiting planet. CoRoT is a Franco-European mission launched at the end of 2006, and one of its main objectives is to detect planetary systems using the transit method.
Aims: In this paper, we present a new method for transit detection and …
Tilts and polarity separation in the sunspot groups and active regions at the ascending and descending phases of the cycle 23
Zharkova, V. V.; Zharkov, S. I.
The Solar Feature Catalogues for sunspots and active regions measured with SOHO/MDI instrument and Ca II K3 spectroheliograph of the Paris-Meudon Observatory are analyzed with the automated classification technique for sunspot groups and active region polarities. We report the first classification results for daily variations of tilt angles (norma…
Longitudinal plasma density variations at Saturn caused by hot electrons
Delamere, P. A.; Bagenal, F.
A non-thermal tail to the electron distribution function has been measured in the inner magnetospheres of both Jupiter and Saturn. These ``hot'' electrons are only a small fraction (<1%) of the total electron density, yet their influence on the gas tori at Jupiter and Saturn is significant. We explore the role of hot electrons in both systems u…
Asteroid 2867 Steins. I. Photometric properties from OSIRIS/Rosetta and ground-based visible observations
Jorda, L.; Lamy, P. L.; Barucci, M. A. +6 more
Context: Asteroid 2867 Steins is the first target of the Rosetta space mission with a flyby scheduled in September 2008.
Aims: An early characterization is needed to optimize the flyby parameters and the science operations and to maximize the scientific return. The aim of this article is to characterize the photometric properties of this aster…
Statistics of young starforming complexes in spiral galaxies using NIR photometry
Dottori, H.; Grosbøl, P.
Aims: Very young stellar clusters and cluster complexes may be embedded in dust lanes along spiral arms in disk galaxies and escape detection in visual bands. Observations in the near-infrared K-band offer an almost unbiased view of such clusters or complexes due to the small attenuation by dust at this wavelength. The objective is to determine th…