Search Publications
Geophysical evolution of Saturn's satellite Phoebe, a large planetesimal in the outer Solar System
Lunine, J. I.; Matson, D. L.; Johnson, T. V. +3 more
Saturn's satellite Phoebe is the best-characterized representative of large outer Solar System planetesimals, thanks to the close flyby by the Cassini spacecraft in June 2004. We explore the information contained in Phoebe's physical properties, density and shape, which are significantly different from those of other icy objects in its size range.…
High Angular Resolution Radio Observations of a Coronal Mass Ejection Source Region at Low Frequencies during a Solar Eclipse
Ramesh, R.; Kathiravan, C.; Barve, Indrajit V. +1 more
We carried out radio observations of the solar corona in the frequency range 109-50 MHz during the annular eclipse of 2010 January 15 from the Gauribidanur Observatory, located about 100 km north of Bangalore in India. The radio emission in the above frequency range originates typically in the radial distance range ≈1.2-1.5 R ⊙ in the "…
Time-dependent modelling of the molecular line emission from shock waves in outflow sources
Pineau des Forêts, G.; Flower, D. R.
We have developed further the technique of time-dependent modelling of magnetohydrodynamic shock waves, with a view to interpreting the molecular line emission from outflow sources. The extensively observed source L1157 B1 was chosen as an exemplar of the application of this technique. The dynamical age of the shock wave model was varied in the ra…
Herschel observations of Cen A: stellar heating of two extragalactic dust clouds
Elbaz, D.; Cooray, A.; Galametz, M. +18 more
We present the first results of a multiwavelength survey, incorporating Herschel-?, Spitzer, GALEX and <fr>Australian Telescope Compact Array (ATCA)</fr> observations, of a 1°× 1° field centred on Centaurus A. As well as detecting the inner lobes of the active galactic nucleus (AGN) jet and counterjet, we have found two clouds, bright …
[C ii] 158 µm line detection of the warm ionized medium in the Scutum-Crux spiral arm tangency
Goldsmith, P. F.; Langer, W. D.; Pineda, J. L. +1 more
Context. The Herschel HIFI GOT C+ Galactic plane [C ii] spectral survey has detected strong emission at the spiral arm tangencies.
Aims: We use the unique viewing geometry of the Scutum-Crux (S-C) tangency nearl = 30° to detect the warm ionized medium (WIM) component traced by [CII] and to study the effects of spiral density waves on Interste…
X-rays from colliding stellar winds: the case of close Wolf-Rayet+O binary systems
Zhekov, Svetozar A.
We have analysed the X-ray emission from a sample of close Wolf-Rayet+O (WR+O) binaries using data from the public Chandra and XMM-Newton archives. Global spectral fits show that two-temperature plasma is needed to match the X-ray emission from these objects, because the hot component (kT > 2 keV) is an important ingredient of the spectral mode…
Characterizing the Atmospheres of Transiting Planets with a Dedicated Space Telescope
Ollivier, M.; Ribas, I.; Encrenaz, T. +12 more
Exoplanetary science is one of the fastest evolving fields of today's astronomical research, continuously yielding unexpected and surprising results. Ground-based planet-hunting surveys, together with dedicated space missions such as Kepler and CoRoT, are delivering an ever-increasing number of exoplanets, over 690, and ESA's Gaia mission will esc…
Globular cluster systems as tracers of environmental effects on Virgo early-type dwarfs
Aguerri, J. A. L.; Sánchez-Janssen, R.
Early-type dwarfs (dEs) are by far the most abundant galaxy population in nearby clusters. Whether these objects are primordial, or the recent end products of the different physical mechanisms that can transform galaxies once they enter these high-density environments, is still a matter of debate. Here we present a novel approach to test these sce…
Density variations within the south polar layered deposits of Mars
Zuber, Maria T.; Plaut, Jeffrey J.; Phillips, Roger J. +3 more
The south polar layered deposits (SPLD) constitute the largest known reservoir of water on Mars. Previous studies solved for the best fit uniform density of the deposits using a forward approach. Here we invert for the lateral density variations in the layered deposit using gravity data from radio tracking of Mars Reconnaissance Orbiter, topograph…
Transiting exoplanets from the CoRoT space mission. XXI. CoRoT-19b: a low density planet orbiting an old inactive F9V-star
Mazeh, T.; Aigrain, S.; Alonso, R. +51 more
Context. Observations of transiting extrasolar planets are of key importance to our understanding of planets because their mass, radius, and mass density can be determined. These measurements indicate that planets of similar mass can have very different radii. For low-density planets, it is generally assumed that they are inflated owing to their p…