Spitzer Space Telescope - Guaranteed Time Observer Proposal #50128


The Spitzer/IRAC Star Formation Reference Survey

Principal Investigator: Giovanni Fazio
           Institution: Harvard-Smithsonian Astrophysical Observatory

     Technical Contact: Matthew Ashby, Harvard-Smithsonian Astrophysical Observatory

Co-Investigators: 
Matthew L. N. Ashby, Harvard-Smithsonian CfA                          
Pauline Barmby, Univ. of Western Ontario, Ontario, CA                 
Sukanya Chakrabarti, Havard-Smithsonian CfA                           
Eduardo Gonzalez-Alfonso, Univ. Alcala, Alcala, Spain                 
Jia-Sheng Huang, Harvard-Smithsonian CfA                              
Suzanne Madden, CEA, Saclay, France                                   
Kai Noeske, Harvard-Smithsonian CfA                                   
Michael Pahre, Harvard-Smithsonian CfA                                
Casey Papovich, Texas A&M University                                  
Thomas Robitaille, St. Andrews Univ., St. Andrews, UK                 
Howard Smith, Harvard-Smithsonian CfA                                 
Eckhard Sturm, MPIE, Garching, Germany                                
Jason Surace, Spitzer Science Center                                  
Zhong Wang, Harvard-Smithsonian CfA                                   
Barbara Whitney, Space Science Institute                              
Steven Willner, Harvard-Smithsonian CfA                               
Hong Wu, National Astronomical Obs., Beijing, China                   
Andreas Zezas, University of Crete, Crete, Greece                     

Science Category: nearby galaxies (z<0.05, v_sys<15,000 km/s) 
 Observing Modes: IracMap 
  Hours Approved: 39.2 

Abstract:
We propose a statistically robust study of 380 nearby, bright star-forming
galaxies of all types to better understand the nature of star formation. The
goal of this IRAC reference survey will be to measure total star formation rates
via 8.0 micron PAH emission, with an emphasis on quantitative comparisons of
multiple global star formation indicators including ultraviolet emission,
H-alpha, and radio continuum measurements. The sample is selected to be fully
representative of the entire ranges of infrared luminosity, dust temperature,
and stellar mass exhibited by star-forming galaxies in the local universe: the
sample galaxies exhibit all existing combinations of these properties with the
minimum overall number, selected in a manner that allows results to be applied
to the entire local galaxy population. Here we propose four-band Spitzer/IRAC
photometry for the 275 out of 380 objects which lack suitable observations in
the Spitzer archive. All sample galaxies already have extensive complementary
data available including global ugrizJHK photometry plus radio continuum
intensities. Most also have GALEX imaging; in addition we have already begun a
ground-based campaign to acquire global H-alpha imaging for the complete sample.
We are submitting this IRAC proposal in the context of a larger campaign that
includes a GTO proposal to complete the MIPS 24 micron imaging, and a GO
proposal to acquire the IRS low-resolution spectroscopy. Although these
companion proposals will significantly increase the scientific return of our
survey program, the success of this proposal is not contingent in any way on any
other Spitzer proposal. Our international team is dedicated, experienced, and
has adequate manpower and institutional resources, with expertise in all the
relevant disciplines to ensure the success of this undertaking. PI Fazio
believes this proposal to be the most important element of his extragalactic GTO
program, and requests that it be assigned first priority.