Search Publications
Evidence for rotationally driven plasma transport in Saturn's magnetosphere
André, N.; Lewis, G. R.; Coates, A. J. +7 more
Radial convective transport of plasma in a rotation-dominated magnetosphere implies alternating longitudinal sectors of cooler, denser plasma moving outward and hotter, more tenuous plasma moving inward. The Cassini Plasma Spectrometer (CAPS) has provided dramatic new evidence of this process operating in the magnetosphere of Saturn. The inward tr…
Nucleus properties of Comet 67P/Churyumov Gerasimenko estimated from non-gravitational force modeling
Gutiérrez, Pedro J.; Davidsson, Björn J. R.
By considering model comet nuclei with a wide range of sizes, prolate ellipsoidal shapes, spin axis orientations, and surface activity patterns, constraints have been placed on the nucleus properties of the primary Rosetta target, Comet 67P/Churyumov-Gerasimenko. This is done by requiring that the model bodies simultaneously reproduce the empirica…
The First Giant Flare from SGR 1806-20: Observations Using the Anticoincidence Shield of the Spectrometer on INTEGRAL
Götz, D.; Mereghetti, S.; von Kienlin, A. +4 more
A giant flare from the soft gamma-ray repeater SGR 1806-20 has been discovered with the International Gamma-Ray Astrophysics Laboratory (INTEGRAL) on 2004 December 27 and detected by many other satellites. This tremendous outburst, the first one observed from this source, was a hundred times more powerful than the two giant flares previously obser…
The Near-Infrared Camera and Multi-Object Spectrometer Ultra Deep Field: Observations, Data Reduction, and Galaxy Photometry
Dickinson, Mark; Franx, Marijn; van Dokkum, Pieter +10 more
This paper describes the observations and data reduction techniques for the version 2.0 images and catalog of the Near-Infrared Camera and Multi-Object Spectrometer Ultra Deep Field (NICMOS UDF) Treasury program. All sources discussed in this paper are based on detections in the combined NICMOS F110W and F160W bands only. The NICMOS images are dri…
Origin and evolution of a cold-based tropical mountain glacier on Mars: The Pavonis Mons fan-shaped deposit
Head, James W.; Marchant, David R.; Shean, David E.
Each of the large Tharsis Montes volcanoes in the equatorial region of Mars has an unusual Amazonian-aged fan-shaped deposit on its west-northwestern flank. On the basis of Viking Orbiter data, the origin of these deposits has been variously ascribed to volcanic, mass-wasting, tectonic, and glacial processes. Using new MGS and Odyssey data, combin…
Fluid lava flows in Gusev crater, Mars
Greeley, Ronald; Williams, David A.; Neukum, Gerhard +6 more
Rocks on the floor of Gusev crater are basaltic in composition, as determined from measurements by the Mars Exploration Rover, Spirit. On the basis of compositional data, models of the basaltic lavas at the time of their emplacement suggest viscosities of 2.3 to 50 Pa . s (dependent on the number of phenocrysts and vesicles that were present), whi…
Plasma sheet turbulence observed by Cluster II
Balogh, A.; Khurana, K. K.; Kistler, L. M. +8 more
Cluster fluxgate magnetometer (FGM) and ion spectrometer (CIS) data are employed to analyze magnetic field fluctuations within the plasma sheet during passages through the magnetotail region in the summers of 2001 and 2002 and, in particular, to look for characteristics of magnetohydrodynamic (MHD) turbulence. Power spectral indices determined fro…
Observations of multiple X-line structure in the Earth's magnetotail current sheet: A Cluster case study
Balogh, A.; Dandouras, I.; Eastwood, J. P. +7 more
Observations of the Earth's magnetotail made by the four Cluster spacecraft on October 2 2003 are presented. Multi-spacecraft analysis is used to show that the variations in field and flow observed in the vicinity of the magnetotail current sheet are most consistent with a series of two active reconnection sites bounding an Earthward moving flux r…
Cassini Imaging Science: Initial Results on Saturn's Atmosphere
Burns, J. A.; Neukum, G.; Wagner, R. +32 more
The Cassini Imaging Science Subsystem (ISS) began observing Saturn in early February 2004. From analysis of cloud motions through early October 2004, we report vertical wind shear in Saturn's equatorial jet and a maximum wind speed of ~375 meters per second, a value that differs from both Hubble Space Telescope and Voyager values. We also report a…
Dynamical modelling of stars and gas in NGC 2974: determination of mass-to-light ratio, inclination and orbital structure using the Schwarzschild method
Krajnović, Davor; Emsellem, Eric; Cappellari, Michele +2 more
We study the large-scale stellar and gaseous kinematics of the E4 galaxy NGC 2974, based on panoramic integral-field data obtained with SAURON. We quantify the velocity maps with Fourier methods (kinemetry), and show that the large-scale kinematics is largely consistent with axisymmetry. We construct general axisymmetric dynamical models for the s…