Document Detail

Hot bubbles from active galactic nuclei as a heat source in cooling-flow clusters.
MedLine Citation:
PMID:  12124617     Owner:  NLM     Status:  PubMed-not-MEDLINE    
Hot, X-ray-emitting plasma permeates clusters of galaxies. The X-ray surface brightness often shows a peak near the centre of the cluster that is coincident with a drop in the entropy of the gas. This has been taken as evidence for a 'cooling flow', where the gas cools by radiating away its energy, and then falls to the centre. Searches for this cool gas have revealed significantly less than predicted, indicating that the mass deposition rate is much lower than expected. Most clusters with cooling flows, however, also host an active galactic nucleus at their centres. These active galactic nuclei can inflate large bubbles of hot plasma that subsequently rise through the cluster 'atmosphere', thus stirring the cooling gas and adding energy. Here we report highly resolved hydrodynamic simulations which show that buoyant bubbles increase the cooling time in the inner regions of clusters and significantly reduce the deposition of cold gas.
Marcus Brüggen; Christian R Kaiser
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Nature     Volume:  418     ISSN:  0028-0836     ISO Abbreviation:  Nature     Publication Date:  2002 Jul 
Date Detail:
Created Date:  2002-07-18     Completed Date:  2002-08-09     Revised Date:  2003-11-03    
Medline Journal Info:
Nlm Unique ID:  0410462     Medline TA:  Nature     Country:  England    
Other Details:
Languages:  eng     Pagination:  301-3     Citation Subset:  -    
International University Bremen, Campus Ring 1, 28759 Bremen, Germany.
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