SÉMINAIRE DU GRECO
"Perturbative reconstruction of a gravitational lens: when mass does not follow light" |
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C. Alard |
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I will comment on the perturbative analysis of a gravitational lens composed of a small group of galaxies. This lens forms a system of 3 tangential arcs which was observed by HST. When analyzed by the perturbative method the HST data allow the reconstruction of the potential in the neighborhood of the critical circle. The potential estimation shows that in this system mass does not follow light. In the first order perturbative theory, the lens is reduced to the knowledge of 2 angular functionals. This approach does not depend on a particular model, and thus allows the reconstruction of non-degenerate quantities. |
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lundi 9 février 2009 - 11:00 Salle des séminaires Évry Schatzman, Institut d'Astrophysique de Paris |
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