Spitzer Space Telescope - General Observer Proposal #60116


Extended Stellar Distributions in M83

Principal Investigator: Kate Barnes
           Institution: Indiana University

     Technical Contact: Daniel Dale, University of Wyoming

Co-Investigators: 
Liese van Zee, Indiana University                                     
Daniel Dale, University of Wyoming                                    
Daniela Calzetti, University of Massachusetts                         
Julianne Dalcanton, University of Washington                          
James Bullock, University of California Irvine                        
Rupali Chandar, University of Toledo                                  

Science Category: nearby galaxies (z<0.05, v_sys<15,000 km/s) 
 Observing Modes: IRAC Post-Cryo Mapping
  Hours Approved: 30 

Abstract:
The outer disks of galaxies provide a unique environment for studies of disk
growth and galaxy formation. Due to the long dynamical timescales in the outer
disk, stellar structures such as breaks, truncations, and tidal streams persist
over billions of years. Deep imaging of these structures allows us to trace the
history of the galaxy's accretion events and evolution, thus providing essential
constraints on current models of galaxy formation. Here we are proposing for
deep IRAC imaging of the prototypical star-forming galaxy, M83, to conduct a
pilot study for a larger survey of the outer disk of nearby galaxies. M83 has a
rich set of ancillary data that will allow for a multiwavelength analysis of the
stellar populations throughout the outer disk. Existing ACS data will allow for
a direct calibration of the observed IR surface brightness to a stellar mass
density. Comparison of deep IR and UV integrated light profiles will reveal
variations in the stellar populations and provide a unique test case for models
of disk growth.