Proof of dark matter existence and other results from a collision of galaxy clusters

par Maxim Markevitch (Harvard-Smithsonian CfA Cambridge, USA/Space Research Inst., Moscow, Russia)

mardi 21 nov. 2006, 16:00 → 17:30 US/Central

Salle 101 (LAL)

Collisions of galaxy clusters are unique experiments that nature stages for us to study the properties of normal and dark matter that are inaccessible by other means. I will review recent results obtained using the merging cluster 1E0657-56. A combination of a long Chandra X-ray observation with accurate weak and strong gravitational lensing maps has provided the first direct, model-independent proof of the dark matter existence (as opposed to the modified gravity paradigm), and a direct constraint on self-interaction cross-section of the dark matter particles. This cluster also exhibits a rare example of a shock front in the intergalactic gas. Its X-ray observations can be used for interesting physical tests, such as determining the electron-ion equilibration timescale in magnetized astrophysical plasmas.

Slides markevitch06.pdf