Institute dAstrophysique Spatial

Orsay, France

Institute dAstrophysique Spatial

Orsay, France
Time filter
Source Type

Andreotti E.,University of Insubria | Andreotti E.,National Institute of Nuclear Physics, Italy | Andreotti E.,Institute for Reference Materials and Measurement | Arnaboldi C.,University of Milan Bicocca | And 107 more authors.
Physical Review C - Nuclear Physics | Year: 2012

The CUORICINO experiment was an array of 62 TeO 2 single-crystal bolometers with a total 130Te mass of 11.3kg. The experiment finished in 2008 after more than 3 yr of active operating time. Searches for both 0ν and 2ν double-β decay to the first excited 0 + state in 130Xe were performed by studying different coincidence scenarios. The analysis was based on data representing a total exposure of N(130Te)•t=9.5×1025yr. No evidence for a signal was found. The resulting lower limits on the half-lives are T122ν (130Te →130Xe *)>1. 3×1023yr (90% C.L.), and T120ν (130Te →130Xe *)>9.4×1023yr (90% CL). ©2012 American Physical Society.

Bishop J.L.,Search for Extraterrestrial Intelligence Institute | Bishop J.L.,NASA | Tirsch D.,German Aerospace Center | Tornabene L.L.,University of Western Ontario | And 21 more authors.
Journal of Geophysical Research E: Planets | Year: 2013

There is ample evidence of both ancient and long-lasting fluvial activity and chemical alteration in the Libya Montes region south of Isidis Basin. The region hosts Noachian to Amazonian aged surface rocks with extensive outcrops of olivine- and pyroxene-bearing material. Libya Montes also features surface outcrops and/or deposits hosting Fe/Mg-smectite, Fe/Mg-smectite mixed with carbonate and/or other Fe/Mg-rich phyllosilicates, and Al-smectite. These units likely formed through chemical alteration connected with hydrothermal activity resulting from the formation of the Isidis Basin and/or the pervasive fluvial activity throughout this region. The morphology and stratigraphy of the aqueous and mafic minerals are described using High Resolution Imaging Science Experiment and High Resolution Stereo Camera derived digital terrain models. Analyses of the Compact Reconnaissance Imaging Spectrometer for Mars spectra show variations in the chemistry of the Fe/Mg-smectite from nontronite-like exposures with spectral features near 2.29 and 2.4 μm more consistent with Fe3+ 2OH groups in the mineral structure, and saponite-like outcrops with spectral features near 2.31 and 2.38 μm characteristic of Mg2+ 3OH groups. These Fe/Mg-smectite bearing materials also have bands near 1.9 μm due to H2O and near 2.5 μm that could be due to the smectite, other phyllosilicates, and carbonates. All regions exhibiting carbonate features near 3.4-3.5 μm also have features consistent with the presence of olivine and Fe/Mg-smectite, indicating that the carbonate signatures occur in rocks likely containing a mixture of these minerals. The Al-smectite-bearing rocks have bands near 1.41, 1.91, and 2.19 μm that are more consistent with beidellite than other Al-phyllosilicates, indicating a higher-temperature or diagenetically processed origin for this material. Our interpretation of the geologic history of this region is that ancient Noachian basaltic crustal materials experienced extensive aqueous alteration at the time of the Isidis impact, during which the montes were also formed, followed by emplacement of a rough olivine-rich lava or melt, and finally the smooth pyroxene-bearing caprock unit. Key Points The Libya Montes region includes Noachian to Amazonian aged surface rocks Surface rocks contain pyroxene, olivine, Fe/Mg-clays, dolomite, and beidellite Aqueous alteration and montes formation were likely induced by the Isidis impact ©2012. American Geophysical Union. All Rights Reserved.

Fraeman A.A.,Washington University in St. Louis | Arvidson R.E.,Washington University in St. Louis | Murchie S.L.,Johns Hopkins Applied Physics Laboratory | Rivkin A.,Johns Hopkins Applied Physics Laboratory | And 7 more authors.
Journal of Geophysical Research E: Planets | Year: 2012

Disk-resolved observations of Phobos acquired by OMEGA at a range of lighting and viewing geometries were fit with the Hapke photometric function to solve for the single particle phase function and single scattering albedos from 0.4 to 2.5m. Single scattering albedos were recovered from CRISM observations of Phobos using the OMEGA derived single particle phase function and are similar to those from OMEGA data. Both the ubiquitous red unit and the blue unit around the crater Stickney exhibit a smooth red-sloped spectrum, with a steeper continuum in the redder unit. Single scattering albedos retrieved from CRISM measurements of Deimos are similar to those for the red unit on Phobos. Retrieval of single scattering albedos from OMEGA data at 2.8 to 5.0m has greater uncertainty, but results in this wavelength range are also consistent with a smooth, red-sloped spectrum. Phobos' and Deimos' low reflectances, lack of mafic absorption features, and red spectral slopes are incompatible with even highly space weathered chondritic or basaltic compositions. These results, coupled with similarities to laboratory spectra of Tagish Lake (possible D-type asteroid analog) and CM carbonaceous chondrite meteorites, show that Phobos and Deimos have primitive compositions. If the moons formed in situ rather than by capture of primitive bodies, primitive materials must have been added to the Martian system during accretion or a late stage impact. © 2012 American Geophysical Union. All Rights Reserved.

Tran H.,University of California at Berkeley | Johnson B.,University of California at Berkeley | Dragovan M.,Jet Propulsion Laboratory | Bock J.,Jet Propulsion Laboratory | And 40 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010

The Experimental Probe of Inflationary Cosmology - Intermediate Mission (EPIC-IM) is a concept for the NASA Einstein Inflation Probe satellite. EPIC-IM is designed to characterize the polarization properties of the Cosmic Microwave Background to search for the B-mode polarization signal characteristic of gravitational waves generated during the epoch of Inflation in the early universe. EPIC-IM employs a large focal plane with 11,000 detectors operating in 9 wavelength bands to provide 30 times higher sensitivity than the currently operating Planck satellite. The optical design is based on a wide-field 1.4 m crossed-Dragone telescope, an aperture that allows not only comprehensive measurements of Inflationary B-mode polarization, but also measurements of the E-mode and lensing polarization signals to cosmological limits, as well as all-sky maps of Galactic polarization with unmatched sensitivity and angular resolution. The optics are critical to measuring these extremely faint polarization signals, and any design must meet demanding requirements on systematic error control. We describe the EPIC-IM crossed Dragone optical design, its polarization properties, and far-sidelobe response. © 2010 SPIE.

Migliorini A.,Istituto di Astrofisica Spaziale e Fisica Cosmica | Altieri F.,National institute for astrophysics | Zasova L.,IKI | Piccioni G.,Istituto di Astrofisica Spaziale e Fisica Cosmica | And 7 more authors.
Planetary and Space Science | Year: 2011

Imaging spectrometers are highly effective instruments for investigation of planetary atmospheres. They present the advantage of coupling the compositional information to the spatial distribution, allowing simultaneous study of chemistry and dynamics in the atmospheres of Venus and Mars. In this work, we summarize recent results about the O2(a1Δ g) night and day glows, respectively obtained by VIRTIS/Venus Express and OMEGA/Mars Express, the imaging spectrometers currently in orbit around Venus and Mars. The case of the O2(a1Δg X3Σg-) IR emission at 1.27 μm on the night side of Venus and the day side of Mars is analyzed, pointing out dynamical aspects of these planets, like the detection of gravity waves in their atmospheres. The monitoring of seasonal and daily airglow variations provides hints about the photochemistry on these planets. © 2010 Elsevier Ltd.

Loading Institute dAstrophysique Spatial collaborators
Loading Institute dAstrophysique Spatial collaborators