M. Giard

Evaluation of the role of organometallic species in the chemistry of interstellar and circumstellar media

Interactions between metal atoms or ions and unsaturated organic molecules in the interstellar or circumstellar media could play an important role in the chemistry of these media.Ab‐initio calculations were performed to predict bonding energy of the cations [metal‐benzene]+ and [Mg‐pyrene]+. We showed that the higher bonding energy of [metal‐benzene]+ is, the larger is the metal depletion. This result should be extended to bigger PAHs. We conclude that organometallic chemistry can participate to the depletion of metals.We synthetized grains composed of small cristallized cores of metal (diameter from 20A to 200A) embedded in pyrene. The mean diameter of grains depends of the ratio pyrene/metal.Finally, we showed that organometallic reactions can be catalytic. Large organic molecules could be synthetized faster in the ISM through such this process than through classical collisions. We propose that the first ring of PAH molecules could be synthetised in this way.

Probing the baryon cycle of galaxies with SPICA mid- and far-infrared observations

The SPICA mid and far-infrared telescope will address fundamental issues in our understanding of star formation and ISM physics in galaxies. A particular hallmark of SPICA is the outstanding sensitivity enabled by the cold telescope, optimized detectors, and wide instantaneous bandwidth throughout the mid- and far-infrared. The spectroscopic, imaging and polarimetric observations that SPICA will be able to collect will help in clarifying the complex physical mechanisms which underlie the baryon cycle of galaxies. In particular: (i) The access to a large suite of atomic and ionic fine-structure lines for large samples of galaxies will shed light on the origin of the observed spread in star formation rates within and between galaxies. (ii) Observations of HD rotational lines (out to

New Insights on the Thermal Dust from the Far-Infrared to the Centimeter

sim

The Galactic Dust as a Foreground to Cosmic Microwave Background Maps

10 Mpc) and fine structure lines such as [CII] 158

French activity in infrared astronomy from stratospheric balloons

mu

SPICA: a joint infrared space observatory (Conference Presentation)

m (out to

SPICA-A Large Cryogenic Infrared Space Telescope : Unveiling the Obscured Universe

sim

Optical Design and Ground Tests, for Pilot, a Balloon Borne Experiment for Astronomy

100 Mpc) will clarify the main reservoirs of interstellar matter in galaxies, including phases where CO does not emit. (iii) Far-infrared spectroscopy of dust and ice features will address uncertainties in the mass and composition of dust in galaxies, and the contributions of supernovae to the interstellar dust budget will be quantified by photometry and monitoring of supernova remnants in nearby galaxies. (iv) Observations of far-infrared cooling lines such as [OI] 63

Bolometer arrays development in the DCMB French collaboration

mu

Large Bolometer Arrays with Superconducting NbSi Sensors for Future Space Experiments

m from star-forming molecular clouds in our Galaxy will evaluate the importance of shocks to dissipate turbulent energy. The paper concludes with requirements for the telescope and instruments, and recommendations for the observing strategy.