Nicolas Bouché
Max-Planck-Inst. Extraterrestrische Physik (MPE) (Garching, Allemagne)
Salle des séminaires Évry Schatzman, Institut d'Astrophysique de Paris
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| « Are strong Mg II absorbers signature of super-winds? » |
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Nicolas Bouché |
| Some of the host-galaxy properties (e.g. L/L^*) of strong Mg II absorbers are known from many years. But, a crucial question remains: what is the origin of the cold gas traced by Mg II in absorption? In order to answer this question, we have measured the mean halo-mass of strong Mg II absorbers using cross-correlation techniques in SDSS/DR3: we found a mean halo-mass of < log M > = 11.94 ± 0.36. We demonstrate that this statistical technique, which does not require any spectroscopic follow-up, does not suffer from contaminants such as stars or foreground and background galaxies. Finally, our results directly imply that the individual Mg II clouds of a system are not virialized in the gaseous halos of the host-galaxy. This result makes sense only in the context of the starburst scenario where Mg II absorbers are produced by supernovae-driven winds. |
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vendredi 16 juin 2006 - 11:00 Salle des séminaires Évry Schatzman, Institut d'Astrophysique de Paris |
| Page web du séminaire / Seminar's webpage |