Search Publications
Phyllosilicates in the Mawrth Vallis region of Mars
Mangold, N.; Bibring, J. -P.; Gendrin, A. +8 more
OMEGA/Mars Express has discovered large outcrops rich in phyllosilicates in the region of Mawrth Vallis, Mars (around 20°W, 25°N). The region is located in Noachian highly cratered terrains, close to the limit of the Martian dichotomy, where the outflow channel Mawrth Vallis cuts the highlands. We have examined this region using OMEGA spectra of t…
The stellar mass density at z ~ 6 from Spitzer imaging of i'-drop galaxies
Bunker, Andrew J.; Stark, Daniel P.; Ellis, Richard S. +4 more
We measure the ages, stellar masses, and star formation histories of z ~ 6 galaxies, observed within 1 Gyr of the big bang. We use imaging from the Hubble Space Telescope (HST) and the Spitzer Space Telescope from the public `Great Observatories Origins Deep Survey' (GOODS), coupled with ground-based near-infrared imaging, to measure their spectra…
Exoplanet HD 209458b: Inflated Hydrogen Atmosphere but No Sign of Evaporation
Ben-Jaffel, Lotfi
Many extrasolar planets orbit closely to their parent star. Their existence raises the fundamental problem of loss and gain in their mass. For exoplanet HD 209458b, reports on an unusually extended hydrogen corona and a hot layer in the lower atmosphere seem to support the scenario of atmospheric inflation by the strong stellar irradiation. Howeve…
Scientific goals for the observation of Venus by VIRTIS on ESA/Venus express mission
Baines, K. H.; Bibring, J. -P.; Langevin, Y. +41 more
The Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) on board the ESA/Venus Express mission has technical specifications well suited for many science objectives of Venus exploration. VIRTIS will both comprehensively explore a plethora of atmospheric properties and processes and map optical properties of the surface through its three chan…
The Stability of the Point-Spread Function of the Advanced Camera for Surveys on the Hubble Space Telescope and Implications for Weak Gravitational Lensing
Gardner, Jonathan P.; Ellis, Richard S.; Leauthaud, Alexie +11 more
We examine the spatial and temporal stability of the Hubble Space Telescope's Advanced Camera for Surveys (ACS) Wide Field Camera (WFC) point-spread function (PSF) using the 2 deg2 COSMOS survey. This is important for studies of weak gravitational lensing, where the ability to deconvolve the PSF from galaxy shapes is of paramount import…
Survey of Magnetic Helicity Injection in Regions Producing X-Class Flares
Georgoulis, M. K.; Rust, D. M.; LaBonte, B. J.
Virtually all X-class flares produce a coronal mass ejection (CME), and each CME carries magnetic helicity into the heliosphere. Using magnetograms from the Michelson Doppler Imager on the Solar and Heliospheric Observatory, we surveyed magnetic helicity injection into 48 X-flare-producing active regions recorded by the MDI between 1996 July and 2…
Direct Measurement of the Ratio of Carbon Monoxide to Molecular Hydrogen in the Diffuse Interstellar Medium
France, Kevin; Burgh, Eric B.; McCandliss, Stephan R.
We have used archival far-ultraviolet spectra from observations made by HST STIS and FUSE to determine the column densities and rotational excitation temperatures for carbon monoxide and molecular hydrogen, respectively, along 23 sight lines to Galactic O and B stars. The reddening values range from E(B-V)=0.07 to 0.62, sampling the diffuse to tra…
Constraints on the parameters of radiatively decaying dark matter from the dark matter halos of the Milky Way and Ursa Minor
Nevalainen, J.; Boyarsky, A.; Ruchayskiy, O.
Aims:We improve the earlier restrictions on parameters of the warm dark matter (DM) in the form of a sterile neutrinos.
Methods: The results were obtained from not observing the DM decay line in the X-ray spectrum of the Milky Way (using the recent XMM-Newton PN blank sky data). We also present a similar constraint coming from the recent XMM-N…
Detection of VHE gamma-ray emission from the distant blazar 1ES 1101-232 with HESS and broadband characterisation
Santangelo, A.; Ripken, J.; Carrigan, S. +122 more
Context: The blazar
Aims: VHE observations of blazars are used to investigate…
SPI observations of the diffuse 60Fe emission in the Galaxy
Wang, W.; Strong, A. W.; Knödlseder, J. +12 more
Aims:Gamma-ray line emission from radioactive decay of 60Fe provides constraints on nucleosynthesis in massive stars and supernovae.
Methods: spectrometer SPI on board INTEGRAL has accumulated nearly three years of data on gamma-ray emission from the Galactic plane. We have analyzed these data with suitable instrumental-background m…