Search Publications
Water ice at low to midlatitudes on Mars
Mustard, John; Forget, François; Vincendon, Mathieu
In this paper, we analyze water ice occurrences at the surface of Mars using near-infrared observations, and we study their distribution with a climate model. Latitudes between 45°S and 50°N are considered. Data from the Observatoire pour la Minéralogie, l'Eau, les Glaces et l'Actitité and the Compact Reconnaissance Imaging Spectrometer for Mars a…
Broadband Study with Suzaku of the Magnetar Class
Hurley, K.; Rea, N.; Enoto, T. +3 more
Broadband (0.8-70 keV) spectra of the persistent X-ray emission from nine magnetars were obtained with Suzaku, including three objects in apparent outburst. The soft X-ray component was detected from all of them, with a typical blackbody temperature of kT ~ 0.5 keV, while the hard-tail component, dominating above ~10 keV, was detected at ~1 mCrab …
Seyfert 2 galaxies in the GeV band: jets and starburst
Walter, R.; Ricci, C.; Dorner, D. +2 more
Context. The Fermi/LAT collaboration recently reported the detection of starburt galaxies in the high energy Γ-ray domain, as well as radio-loud narrow-line Seyfert 1 objects.
Aims: Motivated by the presence of sources close to the location of composite starburst/Seyfert 2 galaxies in the first year Fermi/LAT catalogue, we aim at studying hig…
The role of episodic overturn in generating the surface geology and heat flow on Enceladus
Nimmo, Francis; O'Neill, Craig
The Saturnian satellite Enceladus is enigmatic in that its geologically active south polar region shows high heat flows and geysers not seen elsewhere on the satellite at present; its heavily deformed surface shows an episodic age distribution; and the current observed heat loss exceeds the long-term tidal equilibrium heat production by a factor o…
The Massive Progenitor of the Type II-linear Supernova 2009kr
Van Dyk, Schuyler D.; Filippenko, Alexei V.; Foley, Ryan J. +13 more
We present early-time photometric and spectroscopic observations of supernova (SN) 2009kr in NGC 1832. We find that its properties to date support its classification as Type II-linear (SN II-L), a relatively rare subclass of core-collapse supernovae (SNe). We have also identified a candidate for the SN progenitor star through comparison of pre-exp…
INTEGRAL hard X-ray spectra of the cosmic X-ray background and Galactic ridge emission
Walter, R.; Produit, N.; Courvoisier, T. J. -L. +4 more
Aims: We derive the spectra of the cosmic X-ray background (CXB) and of the Galactic ridge X-ray emission (GRXE) in the ~20-200 keV range from the data of the IBIS instrument aboard the INTEGRAL satellite obtained during the four dedicated Earth-occultation observations in early 2006.
Methods: We analyze the modulation of the IBIS/ISGRI …
A Panoramic View of the Milky Way Analog NGC 891
Rejkuba, M.; Mouhcine, M.; Ibata, R.
Recent panoramic observations of the dominant spiral galaxies of the Local Group have revolutionized our view of how these galaxies assemble their mass. However, it remains completely unclear whether the properties of the outer regions of the Local Group large spirals are typical. Here, we present the first panoramic view of a spiral galaxy beyond…
Water content and wind acceleration in the envelope around the oxygen-rich AGB star IK Tauri as seen by Herschel/HIFI
Waters, L. B. F. M.; Olofsson, H.; Marston, A. P. +25 more
During their asymptotic giant branch evolution, low-mass stars lose a significant fraction of their mass through an intense wind, enriching the interstellar medium with products of nucleosynthesis. We observed the nearby oxygen-rich asymptotic giant branch star IK Tau using the high-resolution HIFI spectrometer onboard Herschel. We report on the f…
Coronal hole boundaries evolution at small scales. II. XRT view. Can small-scale outflows at CHBs be a source of the slow solar wind
Doyle, J. G.; Madjarska, M. S.; Subramanian, S.
Aims: We aim to further explore the small-scale evolution of coronal hole boundaries using X-ray high-resolution and high-cadence images. We intend to determine the fine structure and dynamics of the events causing changes of coronal hole boundaries and to explore the possibility that these events are the source of the slow solar wind.
M…
The geologic evolution of Mars: Episodicity of resurfacing events and ages from cratering analysis of image data and correlation with radiometric ages of Martian meteorites
Jaumann, R.; Neukum, G.; Hoffmann, H. +6 more
We have investigated 12 prominent regions on Mars in detail with respect to their geologic evolution through time on the basis of detailed geologic mapping exercises and determining age relationships through crater counting techniques using imagery. New data in combination with previously obtained data have been analyzed by way of a refined method…