Conduction and the Star-Formation Threshold in Brightest Cluster Galaxies
arXiv:0806.0384 · doi:10.1086/590344
Abstract
Current models of galaxy evolution suggest that feedback from active galactic nuclei is needed to explain the high-luminosity cutoff in the galaxy luminosity function. Exactly how an AGN outflow couples with the ambient medium and suppresses star formation remains poorly understood. However, we have recently uncovered an important clue to how that coupling might work. Observations of H-alpha emission and blue light from the universe's most luminous galaxies, which occupy the centers of galaxy clusters, show that star formation happens only if the minimum specific entropy of the intracluster gas is less than 30 keV cm^2. Here we suggest that this threshold for star formation is set by the physics of electron thermal conduction, implying that conduction is critical for channeling AGN energy input toward incipient star-forming regions and limiting the progress of star formation.
Accepted to ApJ Letters, 5 pages, 4 figures
References in corpus (4)
- Heating Hot Atmospheres with Active Galactic Nuclei
- An Entropy Threshold for Strong H-alpha and Radio Emission in the Cores of Galaxy Clusters
- The origin of molecular hydrogen emission in cooling-flow filaments
- A Global Stability Analysis of Clusters of Galaxies with Conduction and AGN Feedback Heating
Cited by in corpus (6)
- Intracluster Medium Entropy Profiles for a Chandra Archival Sample of Galaxy Clusters
- An Entropy Threshold for Strong H-alpha and Radio Emission in the Cores of Galaxy Clusters
- Anisotropic Thermal Conduction and the Cooling Flow Problem in Galaxy Clusters
- A statistically-selected Chandra sample of 20 galaxy clusters -- II. Gas properties and cool-core/non-cool core bimodality
- 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