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Spitzer IRAC Photometry of JWST Calibration Stars

Krick, Jessica E. and Lowrance, Patrick and Carey, Sean and Laine, Seppo and Grillmair, Carl and Van Dyk, Schuyler D. and Glaccum, William J. and Ingalls, James G. and Rieke, George and Hora, Joseph L. and Fazio, Giovanni G. and Gordon, Karl D. and Bohlin, Ralph C. (2021) Spitzer IRAC Photometry of JWST Calibration Stars. Astronomical Journal, 161 (4). Art. No. 177. ISSN 0004-6256. doi:10.3847/1538-3881/abe390.

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We present infrared photometry of all 36 potential JWST calibrators for which there is archival Spitzer IRAC data. This photometry can then be used to inform the stellar models necessary to provide absolute calibration for all JWST instruments. We describe in detail the steps necessary to measure IRAC photometry from archive retrieval to photometric corrections. To validate our photometry, we examine the distribution of uncertainties from all detections in all four IRAC channels as well as compare the photometry and its uncertainties to those from models, ALLWISE, and the literature. Seventy-five percent of our detections have standard deviations per star of all observations within each channel of less than 3%. The median standard deviations are 1.2%, 1.3%, 1.1%, and 1.9% in [3.6]–[8.0], respectively. We find less than 8% standard deviations in differences of our photometry with ALLWISE and excellent agreement with literature values (less than 3% difference), lending credence to our measured fluxes. JWST is poised to do groundbreaking science, and accurate calibration and cross-calibration with other missions will be part of the underpinnings of that science.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Krick, Jessica E.0000-0002-2413-5976
Lowrance, Patrick0000-0001-8014-0270
Carey, Sean0000-0002-0221-6871
Laine, Seppo0000-0003-1250-8314
Grillmair, Carl0000-0003-4072-169X
Van Dyk, Schuyler D.0000-0001-9038-9950
Ingalls, James G.0000-0003-4714-1364
Rieke, George0000-0003-2303-6519
Hora, Joseph L.0000-0002-5599-4650
Fazio, Giovanni G.0000-0002-0670-0708
Gordon, Karl D.0000-0001-5340-6774
Bohlin, Ralph C.0000-0001-9806-0551
Alternate Title:Spitzer IRAC observations of JWST calibration stars
Additional Information:© 2021. The American Astronomical Society. Received 2020 December 17; revised 2021 February 2; accepted 2021 February 3; published 2021 March 11. We thank the anonymous referee for their time and care in providing very useful comments on this manuscript. This work is based in part 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. This research has made use of NASA's Astrophysics Data System. This research has made use of the NASA/IPAC Infrared Science Archive, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. This research has made use of the VizieR catalog access tool, CDS, Strasbourg, France. The original description of the VizieR service was published in A&AS 143, 23. This research has made use of the SIMBAD database, operated at CDS, Strasbourg, France. The acknowledgments were compiled using the Astronomy Acknowledgment Generator. Facility: Spitzer (IRAC). -
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
Subject Keywords:Photometric standard stars; Infrared photometry; Flux calibration
Issue or Number:4
Classification Code:Unified Astronomy Thesaurus concepts: Photometric standard stars (1232); Infrared photometry (792); Flux calibration (544)
Record Number:CaltechAUTHORS:20210312-143419117
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:108417
Deposited By: Tony Diaz
Deposited On:12 Mar 2021 23:23
Last Modified:16 Nov 2021 19:11

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