Spitzer Space Telescope - Archive Research Proposal #40106


Improving the Photometric Precision of IRAC Channels 1 & 2

Principal Investigator: Kenneth Mighell
           Institution: National Optical Astronomy Observatory (NOAO)

     Technical Contact: Kenneth Mighell, NOAO

Co-Investigators: 
William Hoffmann, Steward Observatory / University of Arizona         
William Glaccum, Caltech/Spitzer Science Center                       

Science Category: stellar populations 
Dollars Approved: 73081 

Abstract:
During the past year, the Principal Investigator has worked closely with
Spitzer's Infrared Array Camera (IRAC) Instrument Team to demonstrate that his
NASA- funded MATPHOT algorithm for precision stellar photometry and astrometry
can yield an improvement in the precision of stellar photometry obtained from
IRAC Ch1 observations of bright stars of more than 100% over the best results
obtained with aperture photometry using the calibration procedures recommended
in the IRAC Data Handbook. We propose to analyze archival observations of bright
stars obtained with IRAC Ch1 and Ch2 with the goal of developing new calibration
procedures that have the potential of significantly improving the precision of
point-source photometry. This timely research effort is intended to enhance the
science return not only of existing IRAC Ch1 and Ch2 observations in the Spitzer
data archive but also those that will be made during Spitzer's warm mission
which will start around April 2009 after all of the cryogen is depleted. One or
more articles describing the new calibration procedures will be submitted for
publication in the refereed literature no later than 1 October 2008; the results
of this archival research effort will also be presented to the space science
community at scientific conferences and posted on a web site dedicated to this
project on the web servers of the National Optical Astronomy Observatory.