Search Publications
Evidence for weathering on early Mars from a comparison with terrestrial weathering profiles
Mangold, N.; Dehouck, E.; Gaudin, A.
Phyllosilicates on Mars are widespread in the ancient crust suggesting the presence of liquid water at the martian surface and therefore warmer conditions during its early history. However, the role of the ancient climate in the alteration process, which produced these phyllosilicates, remains under debate, because similar mineral assemblages can …
Titan: An exogenic world?
Moore, Jeffrey M.; Pappalardo, Robert T.
All landforms on Titan that are unambiguously identifiable can be explained by exogenic processes (aeolian, fluvial, impact cratering, and mass wasting). Previous suggestions of endogenically produced cryovolcanic constructs and flows have, without exception, lacked conclusive diagnostic evidence. The modification of sparse recognizable impact cra…
Detection of CH+ emission from the disc around HD 100546
Pinte, C.; Ménard, F.; Woitke, P. +13 more
Despite its importance in the thermal balance of the gas and in the determination of primeval planetary atmospheres, the chemistry in protoplanetary discs remains poorly constrained with only a handful of detected species. We observed the emission from the disc around the Herbig Be star
Modeling polarimetric radar scattering from the lunar surface: Study on the effect of physical properties of the regolith layer
Heggy, Essam; Wieczorek, Mark A.; Fa, Wenzhe
A theoretical model for radar scattering from the lunar regolith using the vector radiative transfer theory for random media has been developed in order to aid in the interpretation of Mini-SAR data from the Chandrayaan-1 and Lunar Reconnaissance Orbiter missions. The lunar regolith is represented as a homogeneous fine-grained layer with rough upp…
An investigation of the SO 2 content of the venusian mesosphere using SPICAV-UV in nadir mode
Montmessin, Franck; Bertaux, Jean-Loup; Marcq, Emmanuel +4 more
Using the SPICAV-UV spectrometer aboard Venus Express in nadir mode, we were able to derive spectral radiance factors in the middle atmosphere of Venus in the 170-320 nm range at a spectral resolution of R ≃ 200 during 2006 and 2007 in the northern hemisphere. By comparison with a radiative transfer model of the upper atmosphere of Venus, we could…
Solar irradiance variability: a six-year comparison between SORCE observations and the SATIRE model
Krivova, N. A.; Solanki, S.; Harder, J. W. +2 more
Aims: We investigate how well modeled solar irradiances agree with measurements from the SORCE satellite, both for total solar irradiance and broken down into spectral regions on timescales of several years.
Methods: We use the SATIRE model and compare modeled total solar irradiance (TSI) with TSI measurements over the period 25 February…
The HST/ACS Coma Cluster Survey - III. Structural parameters of galaxies using single Sérsic fits
Ferguson, Henry C.; Balcells, Marc; Graham, Alister W. +14 more
We present a catalogue of structural parameters for 8814 galaxies in the 25 fields of the Hubble Space Telescope/ACS Coma Treasury Survey. Parameters from Sérsic fits to the two-dimensional surface brightness distributions are given for all galaxies from our published Coma photometric catalogue with mean effective surface brightness brighter than …
How old are the stars in the halo of NGC 5128 (Centaurus A)?
Rejkuba, M.; Greggio, L.; Harris, W. E. +1 more
Context. NGC 5128 (Centaurus A) is, at the distance of just 3.8 Mpc, the nearest easily observable giant elliptical galaxy. Therefore it is the best target to investigate the early star formation history of an elliptical galaxy.
Aims: Our aims are to establish when the oldest stars formed in NGC 5128, and whether this galaxy formed stars over…
Multiwavelength campaign on Mrk 509. I. Variability and spectral energy distribution
Kaastra, J. S.; Kriss, G. A.; Arav, N. +23 more
Context. Active galactic nuclei (AGN) show a wealth of interesting physical processes, some of which are poorly understood. In a broader context, they play an important role in processes that are far beyond their immediate surroundings, owing to the high emitted power.
Aims: We want to address a number of open questions, including the locatio…
Spectral energy distributions of an AKARI-SDSS-GALEX sample of galaxies
Buat, V.; Burgarella, D.; Noll, S. +5 more
Context. The nearby universe remains the best laboratory to understand the physical properties of galaxies and is a reference for any comparison with high redshift observations. The all sky (or very large) surveys that have been performed from the ultraviolet (UV) to the far-infrared (far-IR) provide us with large datasets of very large wavelength…