Search Publications
Magnetic and optical properties of airborne dust and settling rates of dust at the Phoenix landing site
Morris, R. V.; Drube, L.; Leer, K. +11 more
The Magnetic Properties Experiment (referred to as iSweep or Caltarget) onboard the Phoenix lander was executed in the arctic region of Mars during the mission's 152 sols lifetime. The iSweep experiment involved periodic multispectral imaging of a series of permanent ring magnets. It was designed to attract airborne magnetic dust particles to cert…
HRC-I/Chandra X-ray observations towards σ Orionis
Caballero, J. A.; Albacete-Colombo, J. F.; López-Santiago, J.
Aims: We investigated the X-ray emission from young stars and brown dwarfs in the σ Orionis cluster (τ ~ 3 Ma, d ~ 385 pc) and its relation to mass, the presence of circumstellar discs, and separation to the cluster centre by taking advantage of the superb spatial resolution of the Chandra X-ray Observatory.
Methods: We used public HRC-I…
First results on Martian carbon monoxide from Herschel/HIFI observations
Blommaert, J. A. D. L.; Küppers, M.; Thomas, N. +48 more
We report on the initial analysis of Herschel/HIFI carbon monoxide (CO) observations of the Martian atmosphere performed between 11 and 16 April 2010. We selected the (7-6) rotational transitions of the isotopes 13CO at 771 GHz and C18O and 768 GHz in order to retrieve the mean vertical profile of temperature and the mean vol…
Demonstrations that the Solar Wind is Not Accelerated By Waves or Turbulence
Roberts, D. Aaron
The present work uses observations and theoretical considerations to provide both qualitative and quantitative arguments that hydromagnetic waves, whether turbulent or not, cannot produce the acceleration of the fast solar wind and the related heating of the open solar corona. Waves do exist, and can play a role in the differential heating and acc…
Transit timing analysis of CoRoT-1b
Aigrain, S.; Alonso, R.; Barge, P. +33 more
Context. CoRoT, the pioneer space-based transit search, steadily provides thousands of high-precision light curves with continuous time sampling over periods of up to 5 months. The transits of a planet perturbed by an additional object are not strictly periodic. By studying the transit timing variations (TTVs), additional objects can be detected i…
Brightness of Saturn's rings with decreasing solar elevation
Altobelli, Nicolas; Flandes, Alberto; Spilker, Linda +5 more
Early ground-based and spacecraft observations suggested that the temperature of Saturn's main rings (A, B and C) varied with the solar elevation angle, B'. Data from the composite infrared spectrometer (CIRS) on board Cassini, which has been in orbit around Saturn for more than five years, confirm this variation and have been used to d…
Long-term Spectral Variations of Ultraluminous X-ray Sources in the Interacting Galaxy Systems M 51 and NGC 4490/85
Tsujimoto, Masahiro; Ebisawa, Ken; Matsushita, Kyoko +2 more
Variable ultraluminous X-ray sources (ULXs), which are considered to be black hole binaries (BHBs), are known to show state transitions similar to Galactic BHBs. However, the relation between the ULX states and the Galactic BHB states is still unclear, primarily due to the less well-understood behaviors of ULXs in contrast to the Galactic BHBs. He…
NGC 4262: a Virgo galaxy with an extended ultraviolet ring
Buson, L. M.; Bettoni, D.; Galletta, G.
Context. The Galaxy Ultraviolet Explorer (GALEX) satellite has recently shown the presence of an extended, outer ring studded with UV-bright knots surrounding the lenticular galaxy NGC 4262. Such a structure-not detected in the optical-is coupled with a ring of atomic (HI) gas.
Aims: We want to show that both star-forming and HI rings surroun…
Disk evaporation in a planetary nebula
Zijlstra, A. A.; Lagadec, E.; Hajduk, M. +3 more
Aims: Binary interactions are believed to be important contributors to the structures seen in planetary nebulae (PN), and the sole cause of the newly discovered compact dust disks. The evolution of these disks is not clear, nor are the binary parameters required for their creation.
Methods: Using HST imaging and VLT spectroscopy, both lo…
NO emissions as observed by SPICAV during stellar occultations
Montmessin, Franck; Bertaux, Jean-Loup; Royer, Emilie
Ultraviolet (UV) nightglow data from the SPICAV instrument (SPectroscopy for the Investigation of the Characteristics of the Atmosphere of Venus) onboard the Venus Express spacecraft, currently in orbit around Venus, are presented. In its extended source mode, SPICAV has shown that the Venus nightglow in the UV contains essentially Lyman- α and Ni…