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Calibration and data quality of warm IRAC

Carey, S. J. and Surace, J. A. and Glaccum, W. J. and Ingalls, J. and Krick, J. E. and Lacy, M. and Lowrance, P. and Laine, S. and O'Linger, J. and Stauffer, J. R. and Willner, S. P. and Hora, J. L. and Hoffmann, W. F. and Ashby, M. L. N. and Huang, J.-S. and Maregno, M. and Pahre, M. and Wang, Z. and Werner, M. and Fazio, G. G. (2010) Calibration and data quality of warm IRAC. In: Space telescopes and instrumentation 2010 : optical, infrared, and millimeter wave. Proceedings of SPIE. No.7731. Society of Photo-optical Instrumentation Engineers (SPIE) , Bellingham, WA, Art. No. 77310N. ISBN 978-0-81948-221-1.

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We present an overview of the calibration and properties of data from the IRAC instrument aboard the Spitzer Space Telescope taken after the depletion of cryogen. The cryogen depleted on 15 May 2009, and shortly afterward a two-month- long calibration and characterization campaign was conducted. The array temperature and bias setpoints were revised on 19 September 2009 to take advantage of lower than expected power dissipation by the instrument and to improve sensitivity. The final operating temperature of the arrays is 28.7 K, the applied bias across each detector is 500 mV and the equilibrium temperature of the instrument chamber is 27.55 K. The final sensitivities are essentially the same as the cryogenic mission with the 3.6 μm array being slightly less sensitive (10%) and the 4.5 μm array within 5% of the cryogenic sensitivity. The current absolute photometric uncertainties are 4% at 3.6 and 4.5 μm, and better than milli-mag photometry is achievable for long-stare photometric observations. With continued analysis, we expect the absolute calibration to improve to the cryogenic value of 3%. Warm IRAC operations fully support all science that was conducted in the cryogenic mission and all currently planned warm science projects (including Exploration Science programs). We expect that IRAC will continue to make ground-breaking discoveries in star formation, the nature of the early universe, and in our understanding of the properties of exoplanets.

Item Type:Book Section
Related URLs:
URLURL TypeDescription
Carey, S. J.0000-0002-0221-6871
Surace, J. A.0000-0001-7291-0087
Ingalls, J.0000-0003-4714-1364
Lacy, M.0000-0002-3032-1783
Lowrance, P.0000-0001-8014-0270
Laine, S.0000-0003-1250-8314
Stauffer, J. R.0000-0003-3595-7382
Willner, S. P.0000-0002-9895-5758
Hora, J. L.0000-0002-5599-4650
Ashby, M. L. N.0000-0002-3993-0745
Fazio, G. G.0000-0002-0670-0708
Additional Information:© 2010 SPIE. The authors acknowledge the efforts of our colleagues in the IRAC instrument and instrument support teams in maintaining and characterizing the IRAC instrument as well as the operations teams at the Spitzer Science Center, JPL and Lockheed Martin. This work is based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. Support for this work was provided by NASA through an award issued by JPL/Caltech.
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
Subject Keywords:infrared detectors; space telescopes; Spitzer Space Telescope; IRAC
Series Name:Proceedings of SPIE
Issue or Number:7731
Record Number:CaltechAUTHORS:20110321-084434951
Persistent URL:
Official Citation:S. J. Carey ; J. A. Surace ; W. J. Glaccum ; J. Ingalls ; J. Krick ; M. Lacy ; P. Lowrance ; S. Laine ; J. O'Linger ; J. R. Stauffer ; S. P. Willner ; J. L. Hora ; W. F. Hoffmann ; M. L. N. Ashby ; J.-S. Huang ; M. Marengo ; M. Pahre ; Z. Wang ; M. Werner and G. G. Fazio "Calibration and data quality of warm IRAC", Proc. SPIE 7731, Space Telescopes and Instrumentation 2010: Optical, Infrared, and Millimeter Wave, 77310N (August 04, 2010); doi:10.1117/12.857788;
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:22998
Deposited By: Tony Diaz
Deposited On:21 Mar 2011 21:03
Last Modified:14 Nov 2019 23:54

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