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Poster contributions

Stratospheric Observatory For Infrared Astronomy
Murad Hamidouche, Erick Young, Pamela Marcum, Alfred Krabbe
(USRA- NASA Ames Research Center)
We present one of the new generations of observatories, the Stratospheric Observatory For Infrared Astronomy (SOFIA). This is an airborne observatory consisting of a 2.7-m telescope mounted on a modified Boeing B747-SP airplane. Flying at an up to 45,000 ft (14 km) altitude, SOFIA will observe above more than 99 percent of the Earth atmospheric water vapor. We outline the observatory capabilities and goals. The first-generation science instruments flying on board SOFIA and their main astronomical goals will be presented. The current open call for proposals will be summarized with the necessary information.


A CHANDRA Census of c2d YSOs: Evolution of X-ray Emission
Murad Hamidouche, Michael Jacobson, Leslie Looney
(USRA- NASA Ames Research Center)
We present an analytical study of a large sample of 109 young stellar objects in the X-ray. Unexpectedly, the X-ray energy decreases with time and with column density, while it should increase. We conclude that the youngest YSO protostars, Class0/I, emit X-rays in the 1-8 keV band. The deeply embedded sources with the strongest accretion activity are detected in the hard-band (> 2keV) only. Due to extinction, their soft X-rays are not detected. To explain the decline in energy, we believe that within a timescale of few Myrs the corona cools down via the accretion material, as seen in the accreting pre-main-sequence Herbig AeBe stars.


Mergers vs Accretion
B. L'Huillier, F. Combes, B. Semelin
(LERMA/OP)
According to the hierarchical model, small galaxies form first and merge together to form bigger objects. In parallel, galaxies assemble their mass through accretion from cosmic filaments. Recently, the increased spatial resolution of the cosmological simulations have emphasized that a large fraction of cold gas can be accreted by galaxies. In order to compare the role of the two phenomena and the corresponding star formation history, one has to detect the structures in the numerical simulations and to follow them in time, by building a merger tree.



next up previous
suivant: À propos de ce monter: Session SF2A précédent: Session SF2A
Samuel Boissier 2010-06-16