8th HEAD Meeting, 8-11 September, 2004
Session 1 Galaxy Clusters and the Intergalactic Medium
Oral, Wednesday, September 8, 2004, 9:00-10:30am

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[1.01] Dark Energy studies with galaxy clusters

S.W. Allen (Institute of Astronomy, Cambridge, UK)

I will discuss cosmological constraints from X-ray observations of galaxy clusters, with an emphasis on studies of dark energy. I will present the latest results on the mean matter density, dark energy density and dark energy equation of state from Chandra measurements of the X-ray gas mass fraction in the largest, dynamically relaxed clusters. This method, like supernovae studies, allows us to measure the acceleration of the Universe directly and leads to similar, though entirely independent, constraints. I will highlight the complementary nature of X-ray, cosmic microwave background and supernovae studies - the 'three pillars' of current dark energy work - and show how the combination of these data already provides tight constraints on certain key parameters. Future X-ray studies are likely to play a crucial role in revealing the nature of dark energy.


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Bulletin of the American Astronomical Society, 36 #3
© 2004. The American Astronomical Soceity.