Search Publications
Ionization sources in Titan's deep ionosphere
Galand, Marina; Yelle, Roger; Coates, Andrew +4 more
We analyze a multi-instrumental data set from four Titan encounters by the Cassini spacecraft to investigate in detail the formation of the ionosphere. The data set includes observations of thermospheric and ionospheric species and suprathermal electrons. A model describing the solar and electron energy deposition is used as an organizing element …
Transport of energetic electrons into Saturn's inner magnetosphere
Krupp, N.; Roussos, E.; Johnson, R. E. +8 more
We present energetic electron data obtained by Cassini's Magnetospheric Imaging Instrument in the inner magnetosphere of Saturn. We find here that inward transport and energization processes are consistent with conservation of the first two adiabatic invariants of motion. We model several injections near local midnight, one injection has a maximum…
Discovery of X-ray-emitting O-Ne-Mg-rich Ejecta in the Galactic Supernova Remnant Puppis A
Katsuda, Satoru; Petre, Robert; Hwang, Una +3 more
We report on the discovery of X-ray-emitting O-Ne-Mg-rich ejecta in the middle-aged Galactic O-rich supernova remnant Puppis A with Chandra and XMM-Newton. We use line ratios to identify a low-ionization filament running parallel to the northeastern edge of the remnant that requires super-solar abundances, particularly for O, Ne, and Mg, which we …
Silicon in the dust formation zone of IRC +10216
Ivison, R. J.; Blommaert, J. A. D. L.; Olofsson, G. +36 more
The interstellar medium is enriched primarily by matter ejected from evolved low and intermediate mass stars. The outflows from these stars create a circumstellar envelope in which a rich gas-phase and dust-nucleation chemistry takes place. We observed the nearest carbon-rich evolved star, IRC +10216, using the PACS (55-210 µm) and SPIRE (19…
Gas morphology and energetics at the surface of PDRs: New insights with Herschel observations of NGC 7023
Boulanger, F.; Martin, P. G.; France, K. +37 more
Context. We investigate the physics and chemistry of the gas and dust in dense photon-dominated regions (PDRs), along with their dependence on the illuminating UV field.
Aims: Using Herschel/HIFI observations, we study the gas energetics in NGC 7023 in relation to the morphology of this nebula. NGC 7023 is the prototype of a PDR illuminated b…
Ten years of Hubble Space Telescope observations of the variation of the Jovian satellites' auroral footprint brightness
Nichols, J. D.; Clarke, J. T.; Wannawichian, S.
During the past decade, FUV imaging of Jupiter's auroral region by the Hubble Space Telescope (HST) using two instruments, the Space Telescope Imaging Spectrograph (STIS) and the Advanced Camera for Surveys (ACS), has provided detailed information on the electrodynamic interaction between Io's, Ganymede's, and Europa's atmospheres and plasma in Ju…
Multiple harmonic ULF waves in the plasma sheet boundary layer: Instability analysis
RèMe, H.; Keiling, A.; Walsh, A. P. +5 more
Multiple-harmonic electromagnetic waves in the ULF band have occasionally been observed in Earth's magnetosphere, both near the magnetic equator in the outer plasmasphere and in the plasma sheet boundary layer (PSBL) in Earth's magnetotail. Observations by the Cluster spacecraft of multiple-harmonic electromagnetic waves with fundamental frequency…
Direct Detection of an Ultraluminous Ultraviolet Source
Tao, Lian; Feng, Hua; Kaaret, Philip +1 more
We present Hubble Space Telescope observations in the far UV of the ultraluminous X-ray source in NGC 6946 associated with the optical nebula MF 16. Both a point-like source coincident with the X-ray source and the surrounding nebula are detected in the FUV. The point source has a flux of 5 × 10-16 erg s-1 cm-2 Å
The cratering history of asteroid (2867) Steins
Lamy, P.; Keller, H. U.; Mottola, S. +8 more
The cratering history of main belt asteroid (2867) Steins has been investigated using OSIRIS imagery acquired during the Rosetta flyby that took place on the 5th of September 2008. For this purpose, we applied current models describing the formation and evolution of main belt asteroids, that provide the rate and velocity distributions of impactors…
Cassini observations of narrowband radio emissions in Saturn's magnetosphere
Gurnett, D. A.; Russell, C. T.; Kurth, W. S. +5 more
The Radio and Plasma Wave Science instrument (RPWS) on board the Cassini spacecraft has detected numerous narrowband radio emissions in Saturn's magnetosphere from September 2005 to May 2007. Typically, the narrowband radio emissions occur after an intensification of Saturn kilometric radiation (SKR) and last for several days. These emissions ofte…