Search Publications
Accretion-Inhibited Star Formation in the Warm Molecular Disk of the Green-valley Elliptical Galaxy NGC 3226?
Duc, P. -A.; Armus, L.; Appleton, P. N. +7 more
We present archival Spitzer photometry and spectroscopy and Herschel photometry of the peculiar "Green Valley" elliptical galaxy NGC 3226. The galaxy, which contains a low-luminosity active galactic nucleus (AGN), forms a pair with NGC 3227 and is shown to lie in a complex web of stellar and H I filaments. Imaging at 8 and 16 µm reveals a cu…
A model of the spatial and size distribution of Enceladus' dust plume
Kriegel, Hendrik; Motschmann, Uwe; Schmidt, Jürgen +5 more
The structure of Enceladus' south polar plume of charged dust is studied by simulations of the dust grain dynamics. The model considers the Lorentz force and charging of the grains by the plasma environment within the plume. Simulated dust plumes are investigated by applying 10 selected sets of dust parameters that include variations of the grain …
The Phobos information system
Oberst, J.; Karachevtseva, I. P.; Zubarev, A. E. +7 more
We have developed a Geo-information system (GIS) for Phobos, based on data from the Mars Express and Viking Orbiter missions, which includes orthoimages, global maps, terrain- and gravity field models, all referenced to the Phobos coordinate system. The data are conveniently stored in the ArcGIS software system, which provides an environment for m…
The transit spectra of Earth and Jupiter
Aigrain, S.; Fletcher, L. N.; Lee, J. -M. +3 more
In recent years, an increasing number of observations have been made of the transits of 'Hot Jupiters', such as HD 189733b, about their parent stars from the visible through to mid-infrared wavelengths, which have been modelled to derive the likely atmospheric structure and composition of these planets. As measurement techniques improve, the measu…
Carbon dioxide opacity of the Venus' atmosphere
Piccioni, Giuseppe; Adriani, Alberto; Grassi, Davide +2 more
Venus' atmosphere consists of about 95% of carbon dioxide, which accounts for most of the absorption of the radiation emitted by its hot surface. The large densities and high temperatures of Venus' atmosphere make the absorption much more complex than for low density atmospheres such as Earth or Mars. Available experimental data are at present ins…
Thermal structure of a hot non-flaring corona from Hinode/EIS
Del Zanna, G.; Reale, F.; Testa, P. +1 more
Aims: In previous studies, a very hot plasma component has been diagnosed in solar active regions through the images in three different narrow-band channels of Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO). This diagnostic from extreme ultraviolet (EUV) imaging data has also been supported by the matching mo…
Elemental Abundances in the Solar Corona as Measured by the X-ray Solar Monitor Onboard Chandrayaan-1
Alha, L.; Huovelin, J.; Narendranath, S. +3 more
The X-ray Solar Monitor (XSM) on the Indian lunar mission Chandrayaan-1 was flown to complement lunar elemental abundance studies by the X-ray fluorescence experiment C1XS. XSM measured the ≈ 1.8 - 20 keV solar X-ray spectrum during its nine months of operation in lunar orbit. The soft X-ray spectra can be used to estimate absolute coronal abundan…
Keogram analysis of ENA images at Saturn
Mitchell, D. G.; Carbary, J. F.
Keograms are constructed from azimuthal profiles of energetic hydrogen atoms (25-55 keV) from Saturn's magnetosphere. The keograms exhibit linear structures or "tracks" that reveal prograde rotational motion of features or "blobs" in the energetic neutral atom (ENA) images. From polynomial fits, the first derivatives of these tracks are used to es…
Optical and X-ray properties of CAL 83 - II. An X-ray pulsation at ∼67 s
Charles, P. A.; Meintjes, P. J.; Odendaal, A. +1 more
CAL 83 is the prototypical close binary supersoft X-ray source in the Large Magellanic Cloud, has a 1 d orbital period, and is believed to consist of a white dwarf (WD) primary accreting from an evolved donor. Based on published WD model atmosphere fits to X-ray data, the WD has a mass of ∼1.3 M⊙, just below the Chandrasekhar limit. Fro…
STREGA: STRucture and Evolution of the GAlaxy - I. Survey overview and first results
Di Criscienzo, M.; Prada Moroni, P. G.; Degl'Innocenti, S. +28 more
STREGA (STRucture and Evolution of the GAlaxy) is a guaranteed time survey being performed at the VST (the ESO Very Large Telescope Survey Telescope) to map about 150 square degrees in the Galactic halo, in order to constrain the mechanisms of galactic formation and evolution. The survey is built as a 5 yr project, organized in two parts: a core p…