Search Publications
Feasibility and performances of compressed sensing and sparse map-making with Herschel/PACS data
Sauvage, M.; Starck, J. -L.; Chanial, P. +2 more
The Herschel Space Observatory of ESA was launched in May 2009 and has been in operation ever since. From its distant orbit around L2, it needs to transmit a huge quantity of information through a very limited bandwidth. This is especially true for the PACS imaging camera, which needs to compress its data far more than what can be achieved with lo…
ROY—A multiscale magnetospheric mission
Novikov, D.; Kozak, L.; Amata, E. +21 more
The scientific rationale of the ROY multi-satellite mission addresses multiscale investigations of plasma processes in the key magnetospheric regions with strong plasma gradients, turbulence and magnetic field annihilation in the range from electron inertial length to MHD scales. The main scientific aims of ROY mission include explorations of:
Characterization of solar-cycle induced frequency shift of medium- and high-degree acoustic modes
Rabello-Soares, M. Cristina
Although it is well known that the solar acoustic mode frequency increases as the solar activity increases, the mechanism behind it is still unknown. Mode frequencies with 20 < l < 900 obtained by applying spherical harmonic decomposition to MDI full-disk observations were used. First, the dependence of solar acoustic mode frequency with sol…
ENA periodicities and their phase relations to SKR emissions at Saturn
Gurnett, D. A.; Krimigis, S. M.; Mitchell, D. G. +2 more
Cassini orbits during days 200-366 in 2004 afforded the opportunity to continuously observe energetic neutral atom (ENA) emissions from long range (>50 RS, 1 RS = 60268 km) on Saturn's dawn side. Images of energetic neutral hydrogen (25-55 keV) and oxygen (90-160 keV) were projected onto the noon-midnight plane, corrected …
Key results from an XMM-Newton and Chandra study of a new sample of extreme ULXs from the 2XMM catalogue
Roberts, T. P.; Walton, D. J.; Sutton, A. D.
We present highlights from a study of a sample of 10 extreme-luminosity candidate ultraluminous X-ray sources (L_X>5 × 1040 erg s-1), all at distances <100 Mpc, identified from a cross-correlation of the RC3 catalogue of galaxies with the 2XMM catalogue. Five of the sample have also been observed by Chandra. Of the 10 s…
Representation of solar features in 3D for creating visual solar catalogues
Colak, Tufan; Qahwaji, Rami; Ipson, Stan +1 more
In this study a method for 3D representation of active regions and sunspots that are detected from Solar and Heliospheric Observatory/Michelson Doppler Imager magnetogram and continuum images is provided. This is our first attempt to create a visual solar catalogue. Because of the difficulty of providing a full description of data in text based ca…
X-Ray Observation of Mars at Solar Minimum with Suzaku
Ezoe, Yuichiro; Ishikawa, Kumi; Ohashi, Takaya +2 more
Mars was observed in X-rays during 2008 April 3-5 for 82 ks with the Japanese Suzaku observatory. Mars has been known to emit X-rays via the scattering of solar X-rays and via charge exchange between neutral atoms in the exosphere and solar-wind ions. Past theoretical studies suggest that the exospheric neutral density may vary by a factor of up t…
Joule heating of the south polar terrain on Enceladus
Khurana, K. K.; Hand, K. P.; Chyba, C. F.
We report that Joule heating in Enceladus, resulting from the interaction of Enceladus with Saturn's magnetic field, may account for 150 kW to 52 MW of power through Enceladus. Electric currents passing through subsurface channels of low salinity and just a few kilometers in depth could supply a source of power to the south polar terrain, providin…
Weakly broadened iron line in the X-ray spectrum of the ultraluminous X-ray source M82 X-1
Caballero-García, M. D.
We present the best quality XMM-Newton and Suzaku data from M82 X-1 so far. We analyse the spectra of this remarkable ultraluminous X-ray (ULX) source in a self-consistent manner. We have disentangled emission from the host galaxy, responsible for the soft X-ray emission (E≤ 2.5 keV), which is successfully described by a two-temperature thermal em…
Fill and spill in Lethe Vallis: a recent flood-routing system in Elysium Planitia, Mars
Balme, M. R.; Gupta, S.; Gallagher, C. J. +1 more