Mars environment simulations for traces of life detection
Search for extraterrestrial life: new challenge Λ Mars: special exobiologic interest for upcoming missions (ESA-EXOMARS, NASA-PHOENIX.) Λ New tools, miniaturized, sensitive biochip development Λ Resistance of these new tools to space conditions? Λ...
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Search for extraterrestrial life: new challenge Λ Mars: special exobiologic interest for upcoming missions (ESA-EXOMARS, NASA-PHOENIX.) Λ New tools, miniaturized, sensitive biochip development Λ Resistance of these new tools to space conditions? Λ Radiation : critical issue Λ Need for simulations to define relevant experiment parameters Λ BiOMAS (Biochip for Organic Matter Analysis in Space) project: funded by the French Space Agency (CNES) € BiOMAS - ARCoR (Antibodies Resistance to Cosmic Radiation)
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Cavities in inner disks: the GM Aurigae case
International audience ; Recent modeling based on unresolved infrared observations of the spectral energy distribution (SED) of GM Aurigae suggests that the inner disk of this single TTauri star is truncated at an inner radius of 25 AU. Aims. We...
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International audience ; Recent modeling based on unresolved infrared observations of the spectral energy distribution (SED) of GM Aurigae suggests that the inner disk of this single TTauri star is truncated at an inner radius of 25 AU. Aims. We attempt to find evidence of this inner hole in the gas distribution, using spectroscopy with high angular resolution. Methods. Using the IRAM array, we obtained high angular resolution (" 1.5”) observations with a high S/N per channel of the 13CO J=2–1 and C18O J=2–1 and of the 13CO J=1–0 lines. A standard parametric disk model is used to fit the line data in the Fourier-plane and to derive the CO disk properties. Our measurement is based on a detailed analysis of the spectroscopic profile from the CO disk rotating in Keplerian velocity. The millimeter continuum, tracing the dust, is also analyzed. Results. We detect an inner cavity of radius 19 ± 4 AU at the 4.5! level. The hole manifests itself by a lack of emission beyond the (projected) Keplerian speed at the inner radius. We also constrain the temperature gradient in the disk. Conclusions. Our data reveal the existence of an inner hole in GM Aur gas disk. Its origin remains unclear, but can be linked to planet formation or to a low mass stellar companion orbiting close to the central star (" 5-15 AU). The frequent finding of inner cavities suggests that either binarity is the most common scenario of star formation in Taurus or that giant planet formation starts early.
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