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The Spitzer Space Telescope Extragalactic First Look Survey: 24 μm Data Reduction, Catalog, and Source Identification

Fadda, Dario and Marleau, Francine R. and Storrie-Lombardi, Lisa J. and Makozov, David and Frayer, David T. and Appleton, P. N. and Armus, L. and Chapman, S. C. and Choi, P. I. and Fang, F. and Heinrichsen, I. and Helou, G. and Im, M. and Lacy, M. and Shupe, D. L. and Soifer, B. T. and Squires, G. K. and Surace, J. and Teplitz, H. I. and Wilson, G. and Yang, L. (2006) The Spitzer Space Telescope Extragalactic First Look Survey: 24 μm Data Reduction, Catalog, and Source Identification. Astronomical Journal, 131 (6). pp. 2859-2876. ISSN 0004-6256. doi:10.1086/504034.

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We present the reduction of the 24 μm data obtained during the first cosmological survey performed by the Spitzer Space Telescope. Images of a region of sky at moderately high Galactic latitude (l = 88.3°, b = +34.9°) were obtained on 2003 December 9-11. The survey consists of a shallow observation of 2.5° × 2° centered at 17h18m, +59°30' (main survey) and a deeper observation of 1° × 0.5° centered at 17h17m, +59°45' (verification survey). Issues with the reduction of the 24 μm MIPS data are discussed and solutions to attenuate instrumental effects are proposed and applied to the data. Approximately 17,000 sources are extracted with a signal-to-noise ratio (S/N) greater than 5. The photometry of the point sources is evaluated through point-spread function (PSF) fitting using an empirical PSF derived from the data. Aperture corrections and the absolute calibration have been checked using stars in the field. Astrometric and photometric errors depend on the S/N of the source varying between 0farcs35^-1" and 5%-15%, respectively, for sources detected at 20-5 σ. The fluxes of the 123 extended sources have been estimated through aperture photometry. The extended sources cover less than 0.3% of the total area of the survey. Based on simulations, the main and verification surveys are 50% complete at 0.3 and 0.15 mJy, respectively. Counterparts have been searched for in optical and radio catalogs. More than 80% of the 24 μm sources have a reliable optical counterpart down to R = 25.5; 16% of the sources have a 20 cm counterpart down to 0.1 mJy and ~80% of the radio-IR associations have a reliable optical counterpart. A residual map is obtained by subtracting point sources detected at the 3 σ level and interpolating the regions occupied by extended sources. Several Galactic clouds with low and intermediate velocities are identified by comparison with neutral hydrogen data from this field.

Item Type:Article
Related URLs:
URLURL TypeDescription
Fadda, Dario0000-0002-3698-7076
Storrie-Lombardi, Lisa J.0000-0002-5987-5210
Frayer, David T.0000-0003-1924-1122
Appleton, P. N.0000-0002-7607-8766
Armus, L.0000-0003-3498-2973
Helou, G.0000-0003-3367-3415
Im, M.0000-0002-8537-6714
Lacy, M.0000-0002-3032-1783
Shupe, D. L.0000-0003-4401-0430
Squires, G. K.0000-0002-1977-5717
Surace, J.0000-0001-7291-0087
Teplitz, H. I.0000-0002-7064-5424
Wilson, G.0000-0002-6572-7089
Additional Information:© 2006. The American Astronomical Society. Received 2005 December 30; accepted 2006 March 6. Print publication: Issue 6 (2006 June). D.F. is grateful to Alberto Noriega-Crespo for enlightening discussions about MIPS data processing issues. We acknowledge also the anonymous referee for useful comments and suggestions.
Group:Infrared Processing and Analysis Center (IPAC)
Subject Keywords:catalogs; infrared: galaxies; surveys; techniques: photometric
Issue or Number:6
Record Number:CaltechAUTHORS:FADaj06
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:13007
Deposited By: Archive Administrator
Deposited On:15 Jan 2009 05:29
Last Modified:08 Nov 2021 22:34

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