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OATS-DAUT SEMINAR
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Speaker: Mark Voit (Michigan State Univ.)

Title: Mysteries of Galaxy Cluster Cores

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Abstract: The cores of galaxy clusters have defied interpretation for almost three decades. Early X-ray observations seemed to imply that the intergalactic gas in a cluster should be cooling and condensing within the central galaxy. Over the course of several billion years, that process of cooling and condensation should have formed an enormous number of stars, far larger than the numbers of stars that are currently observed in the central galaxies of clusters. For some reason, gas is not cooling and condensing at the predicted rate. Recent observations have suggested that active galactic nuclei at the centers of galaxy clusters are supplying the energy that halts condensation, but the way in which that happens remains mysterious. I will discuss some of the latest ideas about what is happening in cluster cores and their cosmological implications.
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