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Normal and unusual transient events in IRAC images

Patten, Brian M. and Hora, Joseph L. and Fazio, Giovanni G. and Barmby, Pauline and Wang, Zhong and Makovoz, David (2004) Normal and unusual transient events in IRAC images. In: Optical, Infrared, and Millimeter Space Telescopes. Proceedings of SPIE. No.5487. Society of Photo-optical Instrumentation Engineers (SPIE) , Bellingham, WA, pp. 223-233. ISBN 9780819454195.

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The Spitzer Space Telescope Infrared Array Camera (IRAC) is a four-channel camera that uses two pairs of 256 x 256 pixel InSb and Si:As IBC detectors to provide simultaneous images at 3.6, 4.5, 5.8, and 8 microns. IRAC experiences a flux of cosmic rays that produce transient events in images from each of the arrays, with 5-7 pixels per second being affected in an IRAC integration. The vast majority of these transient events can be adequately characterized so they can be effectively detected and flagged by a pipeline software module. However, because of the nature of the arrays and their arrangement in the camera structure, a small fraction of the cosmic ray hits on IRAC produce transients with unusual morphologies which cannot be characterized in a general way. We present nominal cosmic ray rates observed for IRAC on-orbit and rates observed during a period of elevated solar proton flux following a series of X-class solar flares in late 2003. We also present a guide for observers to help identify unusual transient events in their data. We comment on the physical nature of the production of many o9f these unusual transients and how this mechanism differs from the production of "normal" transient events.

Item Type:Book Section
Related URLs:
URLURL TypeDescription
Hora, Joseph L.0000-0002-5599-4650
Fazio, Giovanni G.0000-0002-0670-0708
Barmby, Pauline0000-0003-2767-0090
Additional Information:© 2004 Society of Photo-optical Instrumentation Engineers (SPIE). The authors would like to thank Rick Arendt, Jason Surace, and Bill Glaccum (Spitzer Science Center) for additional contributions to this paper. 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 NASA contract 1407. Support for the IRAC instrument was provided by NASA under contract number 960541 issued by JPL.
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
Subject Keywords:infrared detectors, cosmic rays, image processing and artifacts
Series Name:Proceedings of SPIE
Issue or Number:5487
Record Number:CaltechAUTHORS:20181112-065703276
Persistent URL:
Official Citation:Brian Michael Patten, Joseph L. Hora, Giovanni G. Fazio, Pauline Barmby, Zhong Wang, David Makovoz, } "Normal and unusual transient events in IRAC images", Proc. SPIE 5487, Optical, Infrared, and Millimeter Space Telescopes, (12 October 2004); doi: 10.1117/12.550543;
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:90819
Deposited By: Tony Diaz
Deposited On:13 Nov 2018 20:39
Last Modified:16 Nov 2021 03:35

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