Search Publications
Foreshock cavities and internal foreshock boundaries
Schwartz, Steven J.; Billingham, Laurence; Wilber, Mark
We present two case studies of cluster encounters with foreshock cavities. For one event, we are able, for the first time, to accurately relate the observation of a foreshock cavity to the measured position of the bow shock. This allows us to compute the shock angle, a vital parameter in models of foreshock cavity formation, with greater confidenc…
Ducted propagation of chorus waves: Cluster observations
Walker, S. N.; Yearby, K. H.; Khotyaintsev, Yu. V. +4 more
Ducted propagation of whistler waves in the terrestrial magnetosphere-ionosphere system was discussed and studied long before the first in-situ spacecraft measurements. While a number of implicit examples of the existence of ducted propagation have been found, direct observation of ducts has been hampered by the low sampling rates of measurements …
SOHO/SWAN observations of comets with small perihelia: C/2002 V1 (NEAT), C/2002 X5 (Kudo-Fujikawa), 2006 P1 (McNaught) and 96P/Machholz 1
Bertaux, J. -L.; Combi, M. R.; Quémerais, E. +4 more
SWAN, the all-sky hydrogen Lyman-alpha camera on the SOHO spacecraft, designed primarily to image the interplanetary neutral hydrogen around the Sun, also observes comets continuously over large portions of their apparitions to the north and south of the ecliptic and at small solar elongation angles. Because of SOHO’s location at the L1 Lagrange p…
Pressure from dark matter annihilation and the rotation curve of spiral galaxies
Ascasibar, Y.; Wechakama, M.
The rotation curves of spiral galaxies are one of the basic predictions of the cold dark matter paradigm, and their shape in the innermost regions has been hotly debated over the last decades. The present work shows that dark matter annihilation into electron-positron pairs may affect the observed rotation curve by a significant amount. We adopt a…
Candidate subdwarfs and white dwarfs from the 2MASS, Tycho-2, XPM and UCAC3 catalogues
Gontcharov, George A.; Bajkova, Anisa T.; Fedorov, Peter N. +1 more
Photometry from the Two-Micron All-Sky Survey (2MASS), United States Naval Observatory CCD Astrograph Catalog (UCAC3) and SuperCosmos catalogues, together with proper motions from the Tycho-2, Kharkiv Proper Motions (XPM) and UCAC3 catalogues, is used to select all-sky samples of 28 candidate white dwarfs, 1826 evolved and 7641 unevolved subdwarfs…
Spectra from the shocked nebulae revealing turbulence near the Galactic Centre
Contini, M.; Goldman, I.
The spectra emitted from clouds near the Galactic Centre (GC) are investigated calculating the UV-optical-IR lines using the physical parameters and the element abundances obtained by the detailed modelling of mid-IR observations. Graphical representation of the spectra reveals strong lines. Characteristic line ratios calculated at the nebula prov…
Magnetic field modulated dust streams from Jupiter in interplanetary space
Flandes, Alberto; Krüger, Harald; Hamilton, Douglas P. +3 more
High speed dust streams emanating from near Jupiter were first discovered by the Ulysses spacecraft in 1992. Since then the phenomenon has been re-observed by Galileo in 1995, Cassini in 2000, and Ulysses in 2004. The dust grains are expected to be charged to a potential of ∼5 V, which is sufficient to allow the planet's magnetic field to accelera…
The XMM-Newton view of the eclipse and dips of the dwarf nova Z Chamaleontis
Kuulkers, E.; Nucita, A. A.; Ingrosso, G. +3 more
Context. A cataclysmic variable contains a white dwarf that accretes material from a secondary star via the Roche lobe mechanism. Systems with high line-of-sight inclination angles offer the possibility to pinpoint the location of the X-ray emitting region by characterizing the observed eclipse by the secondary star.
Aims: We present an XMM-N…
An ordinary camera in an extraordinary location: Outreach with the Mars Webcam
Scuka, D.; Ormston, T.; Denis, M. +1 more
The European Space Agency's Mars Express mission was launched in 2003 and was Europe's first mission to Mars. On-board was a small camera designed to provide ‘visual telemetry’ of the separation of the Beagle-2 lander. After achieving its goal it was shut down while the primary science mission of Mars Express got underway. In 2007 this camera was …
Revisiting Time History of Events and Macroscale Interactions during Substorms (THEMIS) substorm events implying magnetic reconnection as the substorm trigger
Lui, A. T. Y.
A recent trend in substorm research is the time history approach, motivated by the NASA mission Time History of Events and Macroscale Interactions during Substorms (THEMIS). We revisit three THEMIS substorm events recently reported to indicate magnetic reconnection as the substorm trigger. The evidence for the occurrence of magnetic reconnection i…