Spitzer Space Telescope - General Observer Proposal #60099


IRAC Imaging of SPT Clusters

Principal Investigator: Mark Brodwin
           Institution: National Optical Astronomy Observatory (NOAO)

     Technical Contact: Mark Brodwin, National Optical Astronomy Observatory (NOAO)

Co-Investigators: 
Matthew Ashby, Harvard-CfA                                            
John Carlstrom, U Chicago                                             
Tom Crawford, U Chicago                                               
Giovanni Fazio, Harvard-CfA                                           
Anthony Gonzalez, U Florida                                           
William Holzapfel, UC Berkeley                                        
Adrian Lee, UC Berkeley                                               
Andrea Loehr, Harvard-CfA                                             
Joe Mohr, University of Illinois                                      
Choong Ngeow, University of Illinois                                  
Laurie Shaw, McGill                                                   
Brian Stalder, Harvard                                                
Adam Stanford, UC Davis                                               
Zak Staniszewski, Case Western                                        
Antony Stark, Harvard-CfA                                             
Christopher Stubbs, Harvard                                           
Joaquin Vieira, U Chicago                                             
Alfredo Zenteno, University of Illinois                               

Science Category: galaxy clusters and groups(high-z) 
 Observing Modes: IRAC Post-Cryo Mapping
  Hours Approved: 36.6 

Abstract:
We propose a program to image the first sample of galaxy clusters selected at
mm-wavelengths via the Sunyaev-Zeldovich Effect (SZE). We have chosen a sample
of 84 robust, high-significance clusters (S/N >= 4.5) from the first 350 deg^2
of the ongoing > 1000 deg^2 South Pole Telescope (SPT) SZE survey. These
clusters are selected on total mass, independently of redshift, and as such form
the ideal sample for studies of massive galaxies in rich environments over a
wide range of redshifts. The IRAC data will provide photometric redshifts and
stellar mass estimates for both field galaxies and cluster members, allowing
studies of the cluster IR luminosity and stellar mass function evolution over
the last 10 Gyr in a unique, unbiased cluster sample. Finally, in concert with
our ongoing, extensive multiwavelength and spectroscopic follow-up programs, the
proposed data will allow empirical calibration of the relationship between SZE,
X-ray, IR and dynamical measures of cluster mass, which will ultimately allow
accurate constraints to be placed on the equation of state of dark energy.