Spitzer Space Telescope - General Observer Proposal #80100


Spitzer-HETDEX Exploratory Large Area (SHELA) Survey

Principal Investigator: Casey Papovich
           Institution: Texas A&M University

     Technical Contact: Casey Papovich, Texas A&M University

Co-Investigators: 
Karl Gebhardt, University of Texas                                    
Josh Adams, University of Texas                                       
Peter Behroozi, Stanford University                                   
Ralf Bender, MPE                                                      
Guillermo Blanc, University of Texas                                  
Robin Ciardullo, Penn State University                                
Darren DePoy, Texas A&M University                                    
Roelof de Jong, AIP                                                   
Niv Drory, MPE                                                        
Neal Evans, University of Texas                                       
Maximilian Fabricius, MPE                                             
Steven Finkelstein, Texas A&M University                              
Eric Gawiser, Rutgers University                                      
Jenny Greene, University of Texas                                     
Caryl Gronwall, Penn State University                                 
Gary Hill, University of Texas                                        
Ulirch Hopp, Munich University                                        
Shardha Jogee, University of Texas                                    
Mark Lacy, NRAO                                                       
Martin Landriau, MPE                                                  
Jennifer Marshall, Texas A&M University                               
Sarah Tuttle, University of Texas                                     
Rachel Somerville, STSCI                                              
Matthias Steinmetz, AIP                                               
Nicholas Suntzeff, Texas A&M University                               
Kim-Vy Tran, Texas A&M University                                     
Risa Wechsler, Stanford University                                    
Lutz Wisotzki, AIP                                                    

Science Category: high-z galaxies (z>0.5) 
 Observing Modes: IRAC Post-Cryo Mapping
  Hours Approved: 526.2 

Abstract:
We propose IRAC imaging of a 28 sq deg field with deep optical imaging lying
within the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) Survey. Our
goal is to explore the relationship between galaxy stellar mass, dark halo mass,
and environment during the important cosmic epoch (redshifts 2<z<3) where the
star formation and AGN activity in galaxies peak. The combination of HETDEX
spectroscopy and deep IRAC and optical imaging in our program will provide a
uniquely powerful dataset enabling these goals. Working in blind spectroscopic
mode, HETDEX will obtain redshifts in this field for approximately 200,000
galaxies and map out the cosmic web at redshifts 1.9<z<3.5, over a large
comoving volume of approximately 0.2 Gpc^3, competitive with SDSS at low
redshifts.This volume spans a broad range of environments within the cosmic web,
representative of field, groups, and proto-clusters. The IRAC data will provide
the key missing ingredient by allowing us to measure galaxy stellar masses down
to values well below the characteristic mass of the stellar mass function at
these redshifts. By combining the IRAC data with the halo mass and local density
(environment) measured from clustering statistics in the spectroscopic and
associated trained photometric dataset, we will obtain a detailed view of how
galaxies grow their stellar mass within different dark matter halos and as a
function of environment. Ultimately, this study will advance our understanding
of the physical processes that drive the formation of stars in galaxies and the
build up of stellar mass over cosmic time. In the spirit of Exploratory
programs, SHELA will enable a broad range of scientific explorations beyond our
immediate goals by delivering all science products (images, catalogs, spectra,
and redshifts) to the public.