Search Publications
Martian ice cloud distribution obtained from SPICAM nadir UV measurements
Montmessin, Franck; Bertaux, Jean-Loup; Fussen, Didier +6 more
The Spectroscopy for the Investigation of the Characteristics of the Atmosphere of Mars (SPICAM) instrument on board Mars Express has successfully performed one Martian year of measurements. Nadir UV (200-310 nm) measurements allowed it to build maps of ice cloud optical depth distribution for all seasons. The development and decay of the aphelion…
Earthward flowing plasmoid: Structure and its related ionospheric signature
Zong, Q. -G.; Daly, P. W.; Baker, D. N. +11 more
An earthward moving plasmoid has been observed on 28 October 2002 by the Cluster spacecraft with simultaneous auroral viewing by the IMAGE satellite. This offers the opportunity to ascertain the optical and the evolutional signatures in the ionosphere of the earthward moving plasmoid. The ionospheric signatures observed in this paper are not subst…
Water vapor and silicon monoxide maser observations in the protoplanetary nebula OH 231.8+4.2
Sánchez Contreras, C.; Alcolea, J.; Bujarrabal, V. +2 more
Context: OH 231.8+4.2 is a well studied preplanetary nebula (pPN) around a binary stellar system that shows a remarkable bipolar outflow.
Aims: To study the structure and kinematics of the inner 10-80 AU nebular regions probed by SiO and H2O maser emission, where the agents of wind collimation are expected to operate, in order to gain insights…
Transition Region Emission and Energy Input to Thermal Plasma during the Impulsive Phase of Solar Flares
Raymond, John C.; Ciaravella, A.; Kohl, J. +3 more
The energy released in a solar flare is partitioned between thermal and nonthermal particle energy and lost to thermal conduction and radiation over a broad range of wavelengths. It is difficult to determine the conductive losses and the energy radiated at transition region temperatures during the impulsive phases of flares. We use UVCS measuremen…
Global and local disturbances in the magnetotail during reconnection
Nakamura, R.; Lucek, E. A.; Rème, H. +2 more
We examine Cluster observations of a reconnection event at xGSM=-15.7 RE in the magnetotail on 11 October 2001, when Cluster recorded the current sheet for an extended period including the entire duration of the reconnection event. The onset of reconnection is associated with a sudden orientation change of the ambient magneti…
XMM-Newton observations of the Lockman Hole. V. Time variability of the brightest AGN
Page, M. J.; Barcons, X.; Fabian, A. C. +4 more
This paper presents the results of a study of X-ray spectral and flux variability on time scales from months to years, of the 123 brightest objects (including 46 type-1 AGN and 28 type-2 AGN) detected with XMM-Newton in the Lockman Hole field. We detected flux variability with a significance ≥3σ in ~50% of the objects, including 68 ± 11% and 48 ± …
Hybrid simulation of Titan's magnetic field signature during the Cassini T9 flyby
Dougherty, M. K.; Glassmeier, K. -H.; Bertucci, C. +6 more
Titan's induced magnetotail is analyzed in terms of a three-dimensional hybrid model, treating the electrons as a massless, charge-neutralizing fluid, whereas a completely kinetic approach is used to cover ion dynamics. Since during the T9 flyby of Cassini, the spacecraft passed through Titan's induced magnetotail in a distance of about 4 Titan ra…
Five years of SGR 1900+14 observations with BeppoSAX
Tiengo, A.; Mereghetti, S.; Sidoli, L. +3 more
We present a systematic analysis of all the BeppoSAX data of the soft gamma-ray repeater SGR 1900+14: these observations allowed us to study the long term properties of the source quiescent emission. In the observation carried out before the 1998 giant flare the spectrum in the 0.8-10 keV energy range was harder and there was evidence for a 20-150…
Dynamics, evolution, and structure of Uranus' brightest cloud feature
Sromovsky, L. A.; Fry, P. M.; Showalter, M. R. +3 more
The brightest cloud feature ever observed on Uranus at near-infrared wavelengths was detected on 14 and 15 August 2005, in images obtained with the NIRC2 instrument and adaptive optics (AO) at the 10-m Keck II telescope. The feature has been tracked forward and backward in time, and appears to have existed almost certainly from 5 November 2004 (po…
Aggregate impacts in Saturn's rings
Karjalainen, Raine
Ring particle aggregates are formed in the outer parts of Saturn's main rings. We study how collisions between aggregates can lead to destruction or coalescence of these aggregates, with local N-body simulations taking into account the dissipative impacts and gravitational forces between particles. Impacts of aggregates with different mass ratios …