Spitzer Space Telescope - Archive Research Proposal #50416


Star Formation and AGN Feedback in Brightest Cluster Galaxies

Principal Investigator: Megan Donahue
           Institution: Michigan State University

     Technical Contact: Megan Donahue, Michigan State University

Co-Investigators: 
G. Mark Voit, Michigan State University                               
Kenneth Cavagnolo, Michigan State University                          
Robert O'Connell, University of Virginia                              

Science Category: galaxy clusters and groups(low-z) 
Dollars Approved: 100000 

Abstract:
Feedback from active galactic nuclei at the centers of galaxies clusters has
become crucial to our understanding of star formation in brightest cluster
galaxies (BGCs). X-ray observations have long suggested that intracluster gas
should be condensing and forming stars at the centers of galaxy clusters.
However, observed levels of star formation in these systems are only 1%-10% of
the cooling rate expected from early X-ray imaging. Now Chandra observations are
showing clear signs of AGN feedback in the form of cavities in the X-ray gas,
indicating that AGNs somehow act to limit star formation in BCGs. Yet, in many
BGCs star formation still continues at a reduced level, and there are now
abundant observations in the Spitzer archive that can help us study it. We are
therefore proposing a Spitzer archival program to compare the IR signatures of
star formation in BCGs with X-ray observations of those same systems that
provide information about the history of AGN feedback, in order to clarify the
relationship between star formation and feedback in the universe's largest
galaxies.