Share Email Print
cover

Proceedings Paper

Absolute photometric calibration of IRAC: lessons learned using nine years of flight data
Author(s): S. Carey; J. Ingalls; J. Hora; J. Surace; W. Glaccum; P. Lowrance; J. Krick; D. Cole; S. Laine; C. Engelke; S. Price; R. Bohlin; K. Gordon
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

Significant improvements in our understanding of various photometric effects have occurred in the more than nine years of flight operations of the Infrared Array Camera aboard the Spitzer Space Telescope. With the accumulation of calibration data, photometric variations that are intrinsic to the instrument can now be mapped with high fidelity. Using all existing data on calibration stars, the array location-dependent photometric correction (the variation of flux with position on the array) and the correction for intra-pixel sensitivity variation (pixel-phase) have been modeled simultaneously. Examination of the warm mission data enabled the characterization of the underlying form of the pixelphase variation in cryogenic data. In addition to the accumulation of calibration data, significant improvements in the calibration of the truth spectra of the calibrators has taken place. Using the work of Engelke et al. (2006), the KIII calibrators have no offset as compared to the AV calibrators, providing a second pillar of the calibration scheme. The current cryogenic calibration is better than 3% in an absolute sense, with most of the uncertainty still in the knowledge of the true flux densities of the primary calibrators. We present the final state of the cryogenic IRAC calibration and a comparison of the IRAC calibration to an independent calibration methodology using the HST primary calibrators.

Paper Details

Date Published: 21 September 2012
PDF: 12 pages
Proc. SPIE 8442, Space Telescopes and Instrumentation 2012: Optical, Infrared, and Millimeter Wave, 84421Z (21 September 2012); doi: 10.1117/12.927183
Show Author Affiliations
S. Carey, Spitzer Science Ctr., California Institute of Technology (United States)
J. Ingalls, Spitzer Science Ctr., California Institute of Technology (United States)
J. Hora, Harvard-Smithsonian Ctr. for Astrophysics (United States)
J. Surace, Spitzer Science Ctr., California Institute of Technology (United States)
W. Glaccum, Spitzer Science Ctr., California Institute of Technology (United States)
P. Lowrance, Spitzer Science Ctr., California Institute of Technology (United States)
J. Krick, Spitzer Science Ctr., California Institute of Technology (United States)
D. Cole, Spitzer Science Ctr., California Institute of Technology (United States)
S. Laine, Spitzer Science Ctr., California Institute of Technology (United States)
C. Engelke, Institute for Scientific Research, Boston College (United States)
S. Price, Institute for Scientific Research, Boston College (United States)
R. Bohlin, Space Telescope Science Institute (United States)
K. Gordon, Space Telescope Science Institute (United States)


Published in SPIE Proceedings Vol. 8442:
Space Telescopes and Instrumentation 2012: Optical, Infrared, and Millimeter Wave
Mark C. Clampin; Giovanni G. Fazio; Howard A. MacEwen; Jacobus M. Oschmann, Editor(s)

© SPIE. Terms of Use
Back to Top