Gerry Gilmore
Institute of Astronomy, University of Cambridge (Cambridge, Royaume-Uni)
Salle des séminaires Évry Schatzman, Institut d'Astrophysique de Paris
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| « How Cold is Cold Dark Matter: dynamics and chemistry of the smallest galaxies » |
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Gerry Gilmore |
| The number and properties of the lowest mass satellites to the Milky Way are a direct test of the nature of Dark Matter on small scales. Many new extremely low luminosity satellites have been discovered recently, mostly by the Cambridge team, including some as-yet unpublished. Kinematic, photometric and abundance analyses of these are underway, providing surprising results. There is a clear minimum half-light size of 100pc for normal dwarf galaxies, perhaps related to a dark matter core scale. The chemical properties at the lowest luminosities are extreme, perhaps resolving inhomegeneous reionisation at high redshift. The associations of the faintest dwarfs with other substructures are unexpected. An update on all these issues will be provided. |
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vendredi 13 mars 2009 - 11:00 Salle des séminaires Évry Schatzman, Institut d'Astrophysique de Paris |
| Page web du séminaire / Seminar's webpage |