Spitzer Space Telescope - General Observer Proposal #40430


Spitzer Observations of the Brightest Lensed LBGs

Principal Investigator: Sahar Allam
           Institution: University of Wyoming

     Technical Contact: Sahar Allam, University of Wyoming

Co-Investigators: 
Andrew Baker, Rutgers University                                      
Huan Lin, Fermilab                                                    
Dieter Lutz, MPE-Garching                                             
Alice Shapley, Princeton University                                   
J. Allyn Smith, APSU/Wyoming                                          
Michael Strauss, Princeton University                                 
Douglas Tucker, Fermilab                                              

Science Category: high-z galaxies (z>0.5) 
 Observing Modes: IracMap IrsMap MipsPhot 
  Hours Approved: 15.8

Abstract:
On rare occasions, the otherwise very faint Lyman break galaxies (LBGs) are
magnified by gravitational lensing to provide exceptional targets for detailed
spectroscopic and imaging studies. The primary objective of this proposal is to
constrain the star formation histories and stellar masses of the two brightest
such objects, estimate their bolometric dust luminosities, distinguish between
starburst and AGN bolometric energetics, and compare the detailed rest-frame
mid-IR spectra of dust emission and absorption with known low-redshift
templates. In particular, the magnification of our targets enables a unique
probe of the nature of dust and star formation at high redshift using IRS, which
is simply not possible for typical unlensed UV-selected galaxies at similar
redshifts. We propose Spitzer IRAC and MIP images and IRS low-resolution spectra
of the two newly discovered brightest, lensed LBGs with, using only a modest
amount of Spitzer time (24.6 hours).