Spitzer Space Telescope - General Observer Proposal #30866


Measuring the Stellar Masses of Galaxies at z~7

Principal Investigator: Rychard Bouwens
           Institution: UCO/Lick Observatory

Co-Investigators: 
Garth Illingworth, UCO/Lick Observtory                                
Ivo Labbe, Carnegie Observatories                                     
Daniel Magee, UCO/Lick Observatory                                    

Science Category: high-z galaxies (z>0.5) 
 Observing Modes: IracMap 
  Hours Approved: 34.0 

Abstract:
The two UDF NICMOS parallels contain the deepest optical / near-IR
images available at any point on the sky and provide us with a unique
opportunity to study the high redshift universe.  Over the second of
these parallels, we find several strong z-dropout (z~7 galaxy)
candidates, adding to the ~2-3 other secure candidates we have found
from systematic searches through the HST archive.  We propose to
significantly increase the depth of the IRAC data available over this
field and thus measure stellar masses for these z-dropout candidates.
This may provide us with our best opportunity to model the stellar
populations of objects at z~7, and therefore constrain star formation
at z>7.  In addition, by obtaining deep IRAC data over the ultradeep
ACS+NICMOS imaging data already available, we would have a field
second only to the HUDF in its value for studies of galaxies at z>5.
This would allow for two other significant endeavors:  (1) to set
significant constraints of the redshift of three J-dropout (z~8-11)
candidates found in this field and (2) to do stellar population
modelling on z~5-6 galaxies faintward of what has even been possible
in the HUDF.