An Entropy Threshold for Strong H-alpha and Radio Emission in the Cores of Galaxy Clusters
arXiv:0806.0382 · doi:10.1086/591665
Abstract
Our Chandra X-ray Observatory archival study of intracluster entropy in a sample of 222 galaxy clusters shows that H-alpha and radio emission from the brightest cluster galaxy are much more pronounced when the cluster's core gas entropy is < 30 keV cm^2. The prevalence of H-alpha emission below this threshold indicates that it marks a dichotomy between clusters that can harbor multiphase gas and star formation in their cores and those that cannot. The fact that strong central radio emission also appears below this boundary suggests that AGN feedback turns on when the intracluster medium starts to condense, strengthening the case for AGN feedback as the mechanism that limits star formation in the Universe's most luminous galaxies.
Submitted to ApJ Letters
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Cited by in corpus (6)
- Intracluster Medium Entropy Profiles for a Chandra Archival Sample of Galaxy Clusters
- Anisotropic Thermal Conduction and the Cooling Flow Problem in Galaxy Clusters
- Conduction and the Star-Formation Threshold in Brightest Cluster Galaxies
- Integral field spectroscopy of ionized and molecular gas in cool cluster cores: evidence for cold feedback?
- Observable consequences of kinetic and thermal AGN feedback in elliptical galaxies and galaxy clusters
- Entropy Limit and the Cold Feedback Mechanism in Cooling Flow Clusters